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Whiting KR, Haer-Wigman L, Florijn RJ, van Beek R, Oud MM, Plomp AS, Boon CJF, Kroes HY, Roepman R. Utilization of automated cilia analysis to characterize novel INPP5E variants in patients with non-syndromic retinitis pigmentosa. Eur J Hum Genet 2024:10.1038/s41431-024-01627-6. [PMID: 38806661 DOI: 10.1038/s41431-024-01627-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 03/21/2024] [Accepted: 05/01/2024] [Indexed: 05/30/2024] Open
Abstract
INPP5E encodes inositol polyphosphate-5-phosphatase E, an enzyme involved in regulating the phosphatidylinositol (PIP) makeup of the primary cilium membrane. Pathogenic variants in INPP5E hence cause a variety of ciliopathies: genetic disorders caused by dysfunctional cilia. While the majority of these disorders are syndromic, such as the neuronal ciliopathy Joubert syndrome, in some cases patients will present with an isolated phenotype-most commonly non-syndromic retinitis pigmentosa (RP). Here, we report two novel variants in INPP5E identified in two patients with non-syndromic RP: patient 1 with compound heterozygous variants (c.1516C > T, p.(Q506*), and c.847G > A, p.(A283T)) and patient 2 with a homozygous variant (c.1073C > T, p.(P358L)). To determine whether these variants were causative for the phenotype in the patients, automated ciliary phenotyping of patient-derived dermal fibroblasts was performed for percent ciliation, cilium length, retrograde IFT trafficking, and INPP5E localization. In both patients, a decrease in ciliary length and loss of INPP5E localization in the primary cilia were seen. With these molecular findings, we can confirm functionally that the novel variants in INPP5E are causative for the RP phenotypes seen in both patients. Additionally, this study demonstrates the usefulness of utilizing ciliary phenotyping as an assistant in ciliopathy diagnosis and phenotyping.
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Affiliation(s)
- Kae R Whiting
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ralph J Florijn
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Ronald van Beek
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Machteld M Oud
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Astrid S Plomp
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Hester Y Kroes
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
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2
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Oh R, Woo SJ, Joo K. Whole genome sequencing for inherited retinal diseases in the Korean National Project of Bio Big Data. Graefes Arch Clin Exp Ophthalmol 2024; 262:1351-1359. [PMID: 37947821 DOI: 10.1007/s00417-023-06309-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 10/22/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
PURPOSE This study aimed to analyze the genetic results of inherited retinal diseases (IRDs) and evaluate the diagnostic usefulness of whole genome sequencing (WGS) in the Korean National Project of Bio Big Data. METHODS As part of the Korean National Project of Bio Big Data, WGS was performed on 32 individuals with IRDs with no identified pathogenic variants through whole or targeted exome sequencing. RESULTS Individuals with retinitis pigmentosa (n = 23), cone dystrophy (n = 2), cone-rod dystrophy (n = 2), familial exudative vitreoretinopathy (n = 2), pigmented paravenous chorioretinal atrophy (n = 1), North Carolina macular dystrophy (n = 1), and bull's-eye macular dystrophy (n = 1) were included. WGS revealed genetic mutations in the IQCB1, PRPF31, USH2A, and GUCY2D genes in five cases (15.6%). Two large structural variations and an intronic variant were newly detected in three cases. Two individuals had biallelic missense mutations that were not identified in previous exome sequencing. CONCLUSION With WGS, the causative variants in 15.6% of unsolved IRDs from the Korean National Project of Bio Big Data were identified. Further research with a larger cohort might unveil the diagnostic usefulness of WGS in IRDs and other diseases.
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Affiliation(s)
- Richul Oh
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173beon-gil, Bundang-gu, Seongnam, Gyeonggido, Republic of Korea, 13620
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173beon-gil, Bundang-gu, Seongnam, Gyeonggido, Republic of Korea, 13620
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173beon-gil, Bundang-gu, Seongnam, Gyeonggido, Republic of Korea, 13620.
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Del Pozo-Valero M, Almoallem B, Dueñas Rey A, Mahieu Q, Van Heetvelde M, Jeddawi L, Bauwens M, De Baere E. Autozygome-guided exome-first study in a consanguineous cohort with early-onset retinal disease uncovers an isolated RIMS2 phenotype and a retina-enriched RIMS2 isoform. Clin Genet 2024. [PMID: 38468396 DOI: 10.1111/cge.14517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/13/2024]
Abstract
Leber congenital amaurosis (LCA) and early-onset retinal degeneration (EORD) are inherited retinal diseases (IRD) characterized by early-onset vision impairment. Herein, we studied 15 Saudi families by whole exome sequencing (WES) and run-of-homozygosity (ROH) detection via AutoMap in 12/15 consanguineous families. This revealed (likely) pathogenic variants in 11/15 families (73%). A potential founder variant was found in RPGRIP1. Homozygous pathogenic variants were identified in known IRD genes (ATF6, CRB1, CABP4, RDH12, RIMS2, RPGRIP1, SPATA7). We established genotype-driven clinical reclassifications for ATF6, CABP4, and RIMS2. Specifically, we observed isolated IRD in the individual with the novel RIMS2 variant, and we found a retina-enriched RIMS2 isoform conserved but not annotated in mouse. The latter illustrates potential different phenotypic consequences of pathogenic variants depending on the particular tissue/cell-type specific isoforms they affect. Lastly, a compound heterozygous genotype in GUCY2D in one non-consanguineous family was demonstrated, and homozygous variants in novel candidate genes ATG2B and RUFY3 were found in the two remaining consanguineous families. Reporting these genes will allow to validate them in other IRD cohorts. Finally, the missing heritability of the two unsolved IRD cases may be attributed to variants in non-coding regions or structural variants that remained undetected, warranting future WGS studies.
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Affiliation(s)
- Marta Del Pozo-Valero
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Basamat Almoallem
- Department of Ophthalmology, College of Medicine, King Saud University (KSU), Riyadh, Saudi Arabia
- Department of Ophthalmology, King Saud University Medical City (KSUMC), Riyadh, Saudi Arabia
| | - Alfredo Dueñas Rey
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Quinten Mahieu
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Mattias Van Heetvelde
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Laila Jeddawi
- Pediatric Ophthalmology Division, Dr. Sulaiman AL Habib Medical Group, AL Khobar, Saudi Arabia
| | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
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4
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Hayman T, Millo T, Hendler K, Chowers I, Gross M, Banin E, Sharon D. Whole exome sequencing of 491 individuals with inherited retinal diseases reveals a large spectrum of variants and identification of novel candidate genes. J Med Genet 2024; 61:224-231. [PMID: 37798099 DOI: 10.1136/jmg-2023-109482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/14/2023] [Indexed: 10/07/2023]
Abstract
BACKGROUND Inherited retinal diseases (IRDs) include a range of vision loss conditions caused by variants in different genes. The clinical and genetic heterogeneity make identification of the genetic cause challenging. Here, a cohort of 491 unsolved cases from our cohort of Israeli and Palestinian families with IRDs underwent whole exome sequencing (WES), including detection of CNVs as well as single nucleotide variants (SNVs). METHODS All participants underwent clinical examinations. Following WES on DNA samples by 3 billion, initial SNV analysis was performed by 3 billion and SNV and CNV analysis by Franklin Genoox. The CNVs indicated by the programme were confirmed by PCR followed by gel electrophoresis. RESULTS WES of 491 IRD cases revealed the genetic cause of disease in 51% of cases, of which 11% were due wholly or in part to CNVs. In two cases, we clarified previously incorrect or unclear clinical diagnoses. This analysis also identified ESRRB and DNM1 as potential novel genes. CONCLUSION This analysis is the most extensive one to include CNVs to examine IRD causing genes in the Israeli and Palestinian populations. It has allowed us to identify the causative variant of many patients with IRDs including ones with unclear diagnoses and potential novel genes.
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Affiliation(s)
- Tamar Hayman
- Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Talya Millo
- Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Karen Hendler
- Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Itay Chowers
- Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Menachem Gross
- Otolaryngology/Head and Neck Surgery, Hadassah Medical Center, Jerusalem, Jerusalem, Israel
| | - Eyal Banin
- Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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5
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Lopez Soriano V, Dueñas Rey A, Mukherjee R, Coppieters F, Bauwens M, Willaert A, De Baere E. Multi-omics analysis in human retina uncovers ultraconserved cis-regulatory elements at rare eye disease loci. Nat Commun 2024; 15:1600. [PMID: 38383453 PMCID: PMC10881467 DOI: 10.1038/s41467-024-45381-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 01/19/2024] [Indexed: 02/23/2024] Open
Abstract
Cross-species genome comparisons have revealed a substantial number of ultraconserved non-coding elements (UCNEs). Several of these elements have proved to be essential tissue- and cell type-specific cis-regulators of developmental gene expression. Here, we characterize a set of UCNEs as candidate CREs (cCREs) during retinal development and evaluate the contribution of their genomic variation to rare eye diseases, for which pathogenic non-coding variants are emerging. Integration of bulk and single-cell retinal multi-omics data reveals 594 genes under potential cis-regulatory control of UCNEs, of which 45 are implicated in rare eye disease. Mining of candidate cis-regulatory UCNEs in WGS data derived from the rare eye disease cohort of Genomics England reveals 178 ultrarare variants within 84 UCNEs associated with 29 disease genes. Overall, we provide a comprehensive annotation of ultraconserved non-coding regions acting as cCREs during retinal development which can be targets of non-coding variation underlying rare eye diseases.
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Affiliation(s)
- Victor Lopez Soriano
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Alfredo Dueñas Rey
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | | | - Frauke Coppieters
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
- Department of Pharmaceutics, Ghent University, Ghent, Belgium
| | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Andy Willaert
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.
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Sakti DH, Cornish EE, Nash BM, Jamieson RV, Grigg JR. IMPDH1-associated autosomal dominant retinitis pigmentosa: natural history of novel variant Lys314Gln and a comprehensive literature search. Ophthalmic Genet 2023; 44:437-455. [PMID: 37259572 DOI: 10.1080/13816810.2023.2215310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/11/2023] [Accepted: 05/14/2023] [Indexed: 06/02/2023]
Abstract
BACKGROUND Inosine monophosphate dehydrogenase (IMPDH) is a key regulatory enzyme in the de novo synthesis of the purine base guanine. Mutations in the inosine monophosphate dehydrogenase 1 gene (IMPDH1) are causative for RP10 autosomal dominant retinitis pigmentosa (adRP). This study reports a novel variant in a family with IMPDH1-associated retinopathy. We also performed a comprehensive review of all reported IMPDH1 disease causing variants with their associated phenotype. MATERIALS AND METHODS Multimodal imaging and functional studies documented the phenotype including best-corrected visual acuity (BCVA), fundus photograph, fundus autofluorescence (FAF), full field electroretinogram (ffERG), optical coherence tomography (OCT) and visual field (VF) data were collected. A literature search was performed in the PubMed and LOVD repositories. RESULTS We report 3 cases from a 2-generation family with a novel heterozygous likely pathogenic variant p. (Lys314Gln) (exon 10). The ophthalmic phenotype showed diffuse outer retinal atrophy with mild pigmentary changes with sparse pigmentary changes. FAF showed early macular involvement with macular hyperautofluorescence (hyperAF) surrounded by hypoAF. Foveal ellipsoid zone island can be found in the youngest patient but not in the older ones. The literature review identified a further 56 heterozygous, 1 compound heterozygous, and 2 homozygous variant. The heterozygous group included 43 missense, 3 in-frame, 1 nonsense, 2 frameshift, 1 synonymous, and 6 intronic variants. Exon 10 was noted as a hotspot harboring 18 variants. CONCLUSIONS We report a novel IMPDH1 variant. IMPDH1-associated retinopathy presents most frequently in the first decade of life with early macular involvement.
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Affiliation(s)
- Dhimas H Sakti
- Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
- Department of Ophthalmology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Elisa E Cornish
- Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
- Eye Genetics Research Unit, Children's Medical Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Benjamin M Nash
- Eye Genetics Research Unit, Children's Medical Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children's Hospitals Network, Sydney, New South Wales, Australia
| | - Robyn V Jamieson
- Eye Genetics Research Unit, Children's Medical Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - John R Grigg
- Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
- Eye Genetics Research Unit, Children's Medical Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
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7
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Zufiaurre-Seijo M, García-Arumí J, Duarri A. Clinical and Molecular Aspects of C2orf71/PCARE in Retinal Diseases. Int J Mol Sci 2023; 24:10670. [PMID: 37445847 DOI: 10.3390/ijms241310670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Mutations in the photoreceptor-specific C2orf71 gene (also known as photoreceptor cilium actin regulator protein PCARE) cause autosomal recessive retinitis pigmentosa type 54 and cone-rod dystrophy. No treatments are available for patients with C2orf71 retinal ciliopathies exhibiting a severe clinical phenotype. Our understanding of the disease process and the role of PCARE in the healthy retina significantly limits our capacity to transfer recent technical developments into viable therapy choices. This study summarizes the current understanding of C2orf71-related retinal diseases, including their clinical manifestations and an unclear genotype-phenotype correlation. It discusses molecular and functional studies on the photoreceptor-specific ciliary PCARE, focusing on the photoreceptor cell and its ciliary axoneme. It is proposed that PCARE is an actin-associated protein that interacts with WASF3 to regulate the actin-driven expansion of the ciliary membrane during the development of a new outer segment disk in photoreceptor cells. This review also introduces various cellular and animal models used to model these diseases and provides an overview of potential treatments.
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Affiliation(s)
- Maddalen Zufiaurre-Seijo
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
| | - José García-Arumí
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
| | - Anna Duarri
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
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8
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Toms M, Ward N, Moosajee M. Nuclear Receptor Subfamily 2 Group E Member 3 (NR2E3): Role in Retinal Development and Disease. Genes (Basel) 2023; 14:1325. [PMID: 37510230 PMCID: PMC10379133 DOI: 10.3390/genes14071325] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 07/30/2023] Open
Abstract
NR2E3 is a nuclear hormone receptor gene required for the correct development of the retinal rod photoreceptors. Expression of NR2E3 protein in rod cell precursors suppresses cone-specific gene expression and, in concert with other transcription factors including NRL, activates the expression of rod-specific genes. Pathogenic variants involving NR2E3 cause a spectrum of retinopathies, including enhanced S-cone syndrome, Goldmann-Favre syndrome, retinitis pigmentosa, and clumped pigmentary retinal degeneration, with limited evidence of genotype-phenotype correlations. A common feature of NR2E3-related disease is an abnormally high number of cone photoreceptors that are sensitive to short wavelength light, the S-cones. This characteristic has been supported by mouse studies, which have also revealed that loss of Nr2e3 function causes photoreceptors to develop as cells that are intermediate between rods and cones. While there is currently no available cure for NR2E3-related retinopathies, there are a number of emerging therapeutic strategies under investigation, including the use of viral gene therapy and gene editing, that have shown promise for the future treatment of patients with NR2E3 variants and other inherited retinal diseases. This review provides a detailed overview of the current understanding of the role of NR2E3 in normal development and disease, and the associated clinical phenotypes, animal models, and therapeutic studies.
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Affiliation(s)
- Maria Toms
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK
| | - Natasha Ward
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Mariya Moosajee
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK
- Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
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McClinton B, Crinnion LA, McKibbin M, Mukherjee R, Poulter JA, Smith CEL, Ali M, Watson CM, Inglehearn CF, Toomes C. Targeted nanopore sequencing enables complete characterisation of structural deletions initially identified using exon-based short-read sequencing strategies. Mol Genet Genomic Med 2023:e2164. [PMID: 36934458 DOI: 10.1002/mgg3.2164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/23/2023] [Indexed: 03/20/2023] Open
Abstract
BACKGROUND The widespread adoption of exome sequencing has greatly increased the rate of genetic diagnosis for inherited conditions. However, the detection and validation of large deletions remains challenging. While numerous bioinformatics approaches have been developed to detect deletions from whole - exome sequencing and targeted panels, further work is typically required to define the physical breakpoints or integration sites. Accurate characterisation requires either expensive follow - up whole - genome sequencing or the time - consuming, laborious process of PCR walking, both of which are challenging when dealing with the repeat sequences which frequently intersect deletion breakpoints. The aim of this study was to develop a cost-effective, long-range sequencing method to characterise deletions. METHODS Genomic DNA was amplified with primers spanning the deletion using long-range PCR and the products purified. Sequencing was performed on MinION flongle flowcells. The resulting fast5 files were basecalled using Guppy, trimmed using Porechop and aligned using Minimap2. Filtering was performed using NanoFilt. Nanopore sequencing results were verified by Sanger sequencing. RESULTS Four cases with deletions detected following comparative read-depth analysis of targeted short-read sequencing were analysed. Nanopore sequencing defined breakpoints at the molecular level in all cases including homozygous breakpoints in EYS, CNGA1 and CNGB1 and a heterozygous deletion in PRPF31. All breakpoints were verified by Sanger sequencing. CONCLUSIONS In this study, a quick, accurate and cost - effective method is described to characterise deletions identified from exome, and similar data, using nanopore sequencing.
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Affiliation(s)
- Benjamin McClinton
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK
| | - Laura A Crinnion
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK.,North East and Yorkshire Genomic Laboratory Hub, Central Lab, St James's University Hospital, Leeds, UK
| | - Martin McKibbin
- Department of Ophthalmology, St James's University Hospital, Leeds, UK
| | | | - James A Poulter
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK
| | - Claire E L Smith
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK
| | - Manir Ali
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK
| | - Christopher M Watson
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK.,North East and Yorkshire Genomic Laboratory Hub, Central Lab, St James's University Hospital, Leeds, UK
| | - Chris F Inglehearn
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK
| | - Carmel Toomes
- Leeds Institute of Medical Research, School of Medicine, University of Leeds, Leeds, UK
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10
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de Bruijn SE, Rodenburg K, Corominas J, Ben-Yosef T, Reurink J, Kremer H, Whelan L, Plomp AS, Berger W, Farrar GJ, Ferenc Kovács Á, Fajardy I, Hitti-Malin RJ, Weisschuh N, Weener ME, Sharon D, Pennings RJE, Haer-Wigman L, Hoyng CB, Nelen MR, Vissers LELM, van den Born LI, Gilissen C, Cremers FPM, Hoischen A, Neveling K, Roosing S. Optical genome mapping and revisiting short-read genome sequencing data reveal previously overlooked structural variants disrupting retinal disease-associated genes. Genet Med 2023; 25:100345. [PMID: 36524988 DOI: 10.1016/j.gim.2022.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Structural variants (SVs) play an important role in inherited retinal diseases (IRD). Although the identification of SVs significantly improved upon the availability of genome sequencing, it is expected that involvement of SVs in IRDs is higher than anticipated. We revisited short-read genome sequencing data to enhance the identification of gene-disruptive SVs. METHODS Optical genome mapping was performed to improve SV detection in short-read genome sequencing-negative cases. In addition, reanalysis of short-read genome sequencing data was performed to improve the interpretation of SVs and to re-establish SV prioritization criteria. RESULTS In a monoallelic USH2A case, optical genome mapping identified a pericentric inversion (173 megabase), with 1 breakpoint disrupting USH2A. Retrospectively, the variant could be observed in genome sequencing data but was previously deemed false positive. Reanalysis of short-read genome sequencing data (427 IRD cases) was performed which yielded 30 pathogenic SVs affecting, among other genes, USH2A (n = 15), PRPF31 (n = 3), and EYS (n = 2). Eight of these (>25%) were overlooked during previous analyses. CONCLUSION Critical evaluation of our findings allowed us to re-establish and improve our SV prioritization and interpretation guidelines, which will prevent missing pathogenic events in future analyses. Our data suggest that more attention should be paid to SV interpretation and the current contribution of SVs in IRDs is still underestimated.
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Affiliation(s)
- Suzanne E de Bruijn
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Kim Rodenburg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jordi Corominas
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Janine Reurink
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hannie Kremer
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Hearing and Genes, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura Whelan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Astrid S Plomp
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, Schlieren, Switzerland; Neuroscience Center Zurich (ZNZ), University and ETH Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - G Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Árpád Ferenc Kovács
- 2nd Department of Paediatrics, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Isabelle Fajardy
- Division of Maternal Malnutrition, Department of Perinatal Environment and Health, Lille University, Lille, France; Division Biochemistry and Molecular Biology, Biology and Pathology Center, Lille, France
| | - Rebekkah J Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicole Weisschuh
- Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - Dror Sharon
- Division of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ronald J E Pennings
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Hearing and Genes, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marcel R Nelen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisenka E L M Vissers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kornelia Neveling
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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11
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Peter VG, Kaminska K, Santos C, Quinodoz M, Cancellieri F, Cisarova K, Pescini Gobert R, Rodrigues R, Custódio S, Paris LP, Sousa AB, Coutinho Santos L, Rivolta C. The first genetic landscape of inherited retinal dystrophies in Portuguese patients identifies recurrent homozygous mutations as a frequent cause of pathogenesis. PNAS NEXUS 2023; 2:pgad043. [PMID: 36909829 PMCID: PMC10003751 DOI: 10.1093/pnasnexus/pgad043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/15/2023]
Abstract
Inherited retinal diseases (IRDs) are a group of ocular conditions characterized by an elevated genetic and clinical heterogeneity. They are transmitted almost invariantly as monogenic traits. However, with more than 280 disease genes identified so far, association of clinical phenotypes with genotypes can be very challenging, and molecular diagnosis is essential for genetic counseling and correct management of the disease. In addition, the prevalence and the assortment of IRD mutations are often population-specific. In this work, we examined 230 families from Portugal, with individuals suffering from a variety of IRD diagnostic classes (270 subjects in total). Overall, we identified 157 unique mutations (34 previously unreported) in 57 distinct genes, with a diagnostic rate of 76%. The IRD mutational landscape was, to some extent, different from those reported in other European populations, including Spanish cohorts. For instance, the EYS gene appeared to be the most frequently mutated, with a prevalence of 10% among all IRD cases. This was, in part, due to the presence of a recurrent and seemingly founder mutation involving the deletion of exons 13 and 14 of this gene. Moreover, our analysis highlighted that as many as 51% of our cases had mutations in a homozygous state. To our knowledge, this is the first study assessing a cross-sectional genotype-phenotype landscape of IRDs in Portugal. Our data reveal a rather unique distribution of mutations, possibly shaped by a small number of rare ancestral events that have now become prevalent alleles in patients.
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Affiliation(s)
- Virginie G Peter
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland.,Department of Ophthalmology, Inselspital, Bern University Hospital, Bern 3010, Switzerland
| | - Karolina Kaminska
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland
| | - Cristina Santos
- Department of Ophthalmology, Instituto de Oftalmologia Dr Gama Pinto (IOGP), Lisbon 1169-019, Portugal.,iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa, Lisbon 1169-056, Portugal
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Francesca Cancellieri
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland
| | - Katarina Cisarova
- Department of Computational Biology, University of Lausanne, Lausanne 1015, Switzerland
| | | | - Raquel Rodrigues
- Department of Medical Genetics, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon 1649-035, Portugal
| | - Sónia Custódio
- Department of Medical Genetics, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon 1649-035, Portugal
| | - Liliana P Paris
- Department of Ophthalmology, Instituto de Oftalmologia Dr Gama Pinto (IOGP), Lisbon 1169-019, Portugal
| | - Ana Berta Sousa
- Department of Medical Genetics, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon 1649-035, Portugal.,Laboratory of Basic Immunology, Faculty of Medicine, University of Lisbon, Lisbon 1649-028, Portugal
| | - Luisa Coutinho Santos
- Department of Ophthalmology, Instituto de Oftalmologia Dr Gama Pinto (IOGP), Lisbon 1169-019, Portugal
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel 4031, Switzerland.,Department of Ophthalmology, University of Basel, Basel 4031, Switzerland.,Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
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12
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Velde HM, Huizenga XJJ, Yntema HG, Haer-Wigman L, Beynon AJ, Oostrik J, Pegge SAH, Kremer H, Lanting CP, Pennings RJE. Genotype and Phenotype Analyses of a Novel WFS1 Variant (c.2512C>T p.(Pro838Ser)) Associated with DFNA6/14/38. Genes (Basel) 2023; 14:457. [PMID: 36833385 PMCID: PMC9957259 DOI: 10.3390/genes14020457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/16/2023] Open
Abstract
The aim of this study is to contribute to a better description of the genotypic and phenotypic spectrum of DFNA6/14/38 and aid in counseling future patients identified with this variant. Therefore, we describe the genotype and phenotype in a large Dutch-German family (W21-1472) with autosomal dominant non-syndromic, low-frequency sensorineural hearing loss (LFSNHL). Exome sequencing and targeted analysis of a hearing impairment gene panel were used to genetically screen the proband. Co-segregation of the identified variant with hearing loss was assessed by Sanger sequencing. The phenotypic evaluation consisted of anamnesis, clinical questionnaires, physical examination and examination of audiovestibular function. A novel likely pathogenic WFS1 variant (NM_006005.3:c.2512C>T p.(Pro838Ser)) was identified in the proband and found to co-segregate with LFSNHL, characteristic of DFNA6/14/38, in this family. The self-reported age of onset of hearing loss (HL) ranged from congenital to 50 years of age. In the young subjects, HL was demonstrated in early childhood. At all ages, an LFSNHL (0.25-2 kHz) of about 50-60 decibel hearing level (dB HL) was observed. HL in the higher frequencies showed inter-individual variability. The dizziness handicap inventory (DHI) was completed by eight affected subjects and indicated a moderate handicap in two of them (aged 77 and 70). Vestibular examinations (n = 4) showed abnormalities, particularly in otolith function. In conclusion, we identified a novel WFS1 variant that co-segregates with DFNA6/14/38 in this family. We found indications of mild vestibular dysfunction, although it is uncertain whether this is related to the identified WFS1 variant or is an incidental finding. We would like to emphasize that conventional neonatal hearing screening programs are not sensitive to HL in DFNA6/14/38 patients, because high-frequency hearing thresholds are initially preserved. Therefore, we suggest screening newborns in DFNA6/14/38 families with more frequency-specific methods.
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Affiliation(s)
- Hedwig M. Velde
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Xanne J. J. Huizenga
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Helger G. Yntema
- Department of Human Genetics, Radboudumc, 6525 GA Nijmegen, The Netherlands
- The Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboudumc, 6525 GA Nijmegen, The Netherlands
- The Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Andy J. Beynon
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Jaap Oostrik
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Sjoert A. H. Pegge
- Department of Medical Imaging, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Cris P. Lanting
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6525 GA Nijmegen, The Netherlands
| | - Ronald J. E. Pennings
- Department of Otorhinolaryngology, Radboudumc, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6525 GA Nijmegen, The Netherlands
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13
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Panneman DM, Hitti-Malin RJ, Holtes LK, de Bruijn SE, Reurink J, Boonen EGM, Khan MI, Ali M, Andréasson S, De Baere E, Banfi S, Bauwens M, Ben-Yosef T, Bocquet B, De Bruyne M, de la Cerda B, Coppieters F, Farinelli P, Guignard T, Inglehearn CF, Karali M, Kjellström U, Koenekoop R, de Koning B, Leroy BP, McKibbin M, Meunier I, Nikopoulos K, Nishiguchi KM, Poulter JA, Rivolta C, Rodríguez de la Rúa E, Saunders P, Simonelli F, Tatour Y, Testa F, Thiadens AAHJ, Toomes C, Tracewska AM, Tran HV, Ushida H, Vaclavik V, Verhoeven VJM, van de Vorst M, Gilissen C, Hoischen A, Cremers FPM, Roosing S. Cost-effective sequence analysis of 113 genes in 1,192 probands with retinitis pigmentosa and Leber congenital amaurosis. Front Cell Dev Biol 2023; 11:1112270. [PMID: 36819107 PMCID: PMC9936074 DOI: 10.3389/fcell.2023.1112270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/20/2023] [Indexed: 02/05/2023] Open
Abstract
Introduction: Retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) are two groups of inherited retinal diseases (IRDs) where the rod photoreceptors degenerate followed by the cone photoreceptors of the retina. A genetic diagnosis for IRDs is challenging since >280 genes are associated with these conditions. While whole exome sequencing (WES) is commonly used by diagnostic facilities, the costs and required infrastructure prevent its global applicability. Previous studies have shown the cost-effectiveness of sequence analysis using single molecule Molecular Inversion Probes (smMIPs) in a cohort of patients diagnosed with Stargardt disease and other maculopathies. Methods: Here, we introduce a smMIPs panel that targets the exons and splice sites of all currently known genes associated with RP and LCA, the entire RPE65 gene, known causative deep-intronic variants leading to pseudo-exons, and part of the RP17 region associated with autosomal dominant RP, by using a total of 16,812 smMIPs. The RP-LCA smMIPs panel was used to screen 1,192 probands from an international cohort of predominantly RP and LCA cases. Results and discussion: After genetic analysis, a diagnostic yield of 56% was obtained which is on par with results from WES analysis. The effectiveness and the reduced costs compared to WES renders the RP-LCA smMIPs panel a competitive approach to provide IRD patients with a genetic diagnosis, especially in countries with restricted access to genetic testing.
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Affiliation(s)
- Daan M. Panneman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands,*Correspondence: Daan M. Panneman,
| | - Rebekkah J. Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Lara K. Holtes
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Suzanne E. de Bruijn
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Janine Reurink
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Erica G. M. Boonen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Manir Ali
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, United Kingdom
| | - Sten Andréasson
- Department of Ophthalmology and Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy,Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Béatrice Bocquet
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, Montpellier University Hospital, Sensgene Care Network, ERN-EYE Network, Montpellier, France,Institute for Neurosciences of Montpellier (INM), L’Institut National de la Santé et de la Recherche Médicale, University of Montpellier, L’Institut National de la Santé et de la Recherche Médicale, Montpellier, France
| | - Marieke De Bruyne
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Berta de la Cerda
- Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), Seville, Spain
| | - Frauke Coppieters
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium,Department of Pharmaceutics, Ghent University, Ghent, Belgium
| | - Pietro Farinelli
- Department of Computational Biology, Unit of Medical Genetics, University of Lausanne, Lausanne, Switzerland
| | - Thomas Guignard
- Chromosomal Genetics Unit, University Hospital of Montpellier, Montpellier, France
| | - Chris F. Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, United Kingdom
| | - Marianthi Karali
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy,Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Ulrika Kjellström
- Department of Ophthalmology and Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
| | - Robert Koenekoop
- McGill University Health Center (MUHC) Research Institute, Montreal, QC, Canada,Departments of Paediatric Surgery, Human Genetics, and Adult Ophthalmology, McGill University Health Center, Montreal, QC, Canada
| | - Bart de Koning
- Department of Clinical Genetics, Maastricht University Medical Center+ (MUMC+), Maastricht, Netherlands
| | - Bart P. Leroy
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium,Department of Head & Skin, Ghent University, Ghent, Belgium,Division of Ophthalmology & Center for Cellular & Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Martin McKibbin
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, United Kingdom,Department of Ophthalmology, St. James’s University Hospital, Leeds, United Kingdom
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, University of Montpellier, Montpellier University Hospital, Sensgene Care Network, ERN-EYE Network, Montpellier, France,Institute for Neurosciences of Montpellier (INM), L’Institut National de la Santé et de la Recherche Médicale, University of Montpellier, L’Institut National de la Santé et de la Recherche Médicale, Montpellier, France
| | | | - Koji M. Nishiguchi
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - James A. Poulter
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, United Kingdom
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland,Department of Ophthalmology, University of Basel, Basel, Switzerland,Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Enrique Rodríguez de la Rúa
- Department of Ophthalmology, Retics Patologia Ocular, OFTARED, Instituto de Salud Carlos III, University Hospital Virgen Macarena, Madrid, Spain
| | | | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Yasmin Tatour
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | | | - Carmel Toomes
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, United Kingdom
| | - Anna M. Tracewska
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Hoai Viet Tran
- Oculogenetic Unit, University Eye Hospital Jules Gonin, Geneva, Switzerland
| | - Hiroaki Ushida
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Veronika Vaclavik
- Oculogenetic Unit, University Eye Hospital Jules Gonin, Geneva, Switzerland
| | - Virginie J. M. Verhoeven
- Department of Ophthalmology, Erasmus, Rotterdam, Netherlands,Department of Clinical Genetics, Erasmus, Rotterdam, Netherlands
| | - Maartje van de Vorst
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands,Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, Netherlands
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14
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Vanden Heuvel C, Aldred B, Boulter T, Sullivan R, Ver Hoeve J, Schmitt M. MFRP variant results in nanophthalmos, retinitis pigmentosa, variability in foveal avascular zone. Ophthalmic Genet 2023; 44:83-88. [PMID: 35880649 DOI: 10.1080/13816810.2022.2103835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
BACKGROUND Membrane frizzled-related protein (MFRP) plays a critical role in ocular development. MFRP mutations are known to cause nanophthalmos and, in some cases, retinitis pigmentosa, foveoschisis, and/or optic nerve head (ONH) drusen. The broad clinical spectrum of MFRP mutations necessitates further investigation of specific genotype-phenotype relationships. MATERIALS AND METHODS We reviewed ophthalmologic and genetic medical records of two affected siblings and one unaffected sibling. RESULTS Genetic testing revealed variants MFRP c.855T>A, p.(Cys285*) and MFRP c.1235T>C, p.(Leu412Pro) in trans in the two affected siblings. In both cases, photopic and scotopic responses were markedly reduced on electroretinogram (ERG), with greater decrease in scotopic function. Optical coherence tomography for both siblings revealed non-cystoid thickening. Blunted foveal reflexes were also observed in both siblings. Notably, foveal avascular zone abnormalities were seen on fundus autofluorescence in only one affected sibling. CONCLUSIONS MFRP-related ocular disease may be underrecognized due to its presentation with high hyperopia and possibly subtle retinal findings. Presence of variants MFRP c.855T>A, p.(Cys285*) and MFRP c.1235T>C, p.(Leu412Pro) in trans resulted in nanophthalmos and retinitis pigmentosa without associated foveoschisis or ONH drusen in our patients, consistent with the incomplete phenotype previously described in Neri et al. Abnormalities in the foveal avascular zone have been noted in other case studies and were inconsistently associated with the variants described here, representing a potential area for future investigation.
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Affiliation(s)
- Claire Vanden Heuvel
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Breanna Aldred
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Tyler Boulter
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Rachel Sullivan
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - James Ver Hoeve
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Melanie Schmitt
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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15
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Mc Clinton B, Corradi Z, McKibbin M, Panneman DM, Roosing S, Boonen EGM, Ali M, Watson CM, Steel DH, Cremers FPM, Inglehearn CF, Hitti-Malin RJ, Toomes C. Effective smMIPs-Based Sequencing of Maculopathy-Associated Genes in Stargardt Disease Cases and Allied Maculopathies from the UK. Genes (Basel) 2023; 14:191. [PMID: 36672932 PMCID: PMC9859292 DOI: 10.3390/genes14010191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/13/2023] Open
Abstract
Macular dystrophies are a group of individually rare but collectively common inherited retinal dystrophies characterised by central vision loss and loss of visual acuity. Single molecule Molecular Inversion Probes (smMIPs) have proved effective in identifying genetic variants causing macular dystrophy. Here, a previously established smMIPs panel tailored for genes associated with macular diseases has been used to examine 57 UK macular dystrophy cases, achieving a high solve rate of 63.2% (36/57). Among 27 bi-allelic STGD1 cases, only three novel ABCA4 variants were identified, illustrating that the majority of ABCA4 variants in Caucasian STGD1 cases are currently known. We examined cases with ABCA4-associated disease in detail, comparing our results with a previously reported variant grading system, and found this model to be accurate and clinically useful. In this study, we showed that ABCA4-associated disease could be distinguished from other forms of macular dystrophy based on clinical evaluation in the majority of cases (34/36).
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Affiliation(s)
- Benjamin Mc Clinton
- Leeds Institute of Medical Research, University of Leeds, St James’s University Hospital, Leeds LS9 7TF, UK
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Martin McKibbin
- Leeds Institute of Medical Research, University of Leeds, St James’s University Hospital, Leeds LS9 7TF, UK
- Department of Ophthalmology, St. James’s University Hospital, Leeds LS9 7TF, UK
| | - Daan M. Panneman
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Erica G. M. Boonen
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Manir Ali
- Leeds Institute of Medical Research, University of Leeds, St James’s University Hospital, Leeds LS9 7TF, UK
| | - Christopher M. Watson
- Leeds Institute of Medical Research, University of Leeds, St James’s University Hospital, Leeds LS9 7TF, UK
- North East and Yorkshire Genomic Laboratory Hub, Central Lab, St. James’s University Hospital, Leeds LS9 7TF, UK
| | - David H. Steel
- Sunderland Eye Infirmary, Sunderland SR2 9HP, UK
- The Bioscience Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Chris F. Inglehearn
- Leeds Institute of Medical Research, University of Leeds, St James’s University Hospital, Leeds LS9 7TF, UK
| | - Rebekkah J. Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Carmel Toomes
- Leeds Institute of Medical Research, University of Leeds, St James’s University Hospital, Leeds LS9 7TF, UK
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16
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The Diagnostic Yield of Next Generation Sequencing in Inherited Retinal Diseases: A Systematic Review and Meta-analysis. Am J Ophthalmol 2022; 249:57-73. [PMID: 36592879 DOI: 10.1016/j.ajo.2022.12.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/16/2022] [Accepted: 12/23/2022] [Indexed: 01/01/2023]
Abstract
PURPOSE Accurate genotyping of individuals with inherited retinal diseases (IRD) is essential for patient management and identifying suitable candidates for gene therapies. This study evaluated the diagnostic yield of next generation sequencing (NGS) in IRDs. DESIGN Systematic review and meta-analysis. METHODS This systematic review was prospectively registered (CRD42021293619). Ovid MEDLINE and Ovid Embase were searched on 6 June 2022. Clinical studies evaluating the diagnostic yield of NGS in individuals with IRDs were eligible for inclusion. Risk of bias assessment was performed. Studies were pooled using a random...effects inverse variance model. Sources of heterogeneity were explored using stratified analysis, meta-regression, and sensitivity analysis. RESULTS This study included 105 publications from 28 countries. Most studies (90 studies) used targeted gene panels. The diagnostic yield of NGS was 61.3% (95% confidence interval: 57.8-64.7%; 51 studies) in mixed IRD phenotypes, 58.2% (51.6-64.6%; 41 studies) in rod-cone dystrophies, 57.7% (46.8-68.3%; eight studies) in macular and cone/cone-rod dystrophies, and 47.6% (95% CI: 41.0-54.3%; four studies) in familial exudative vitreoretinopathy. For mixed IRD phenotypes, a higher diagnostic yield was achieved pooling studies published between 2018-2022 (64.2% [59.5-68.7%]), studies using exome sequencing (73.5% [58.9-86.1%]), and studies using the American College of Medical Genetics variant interpretation standards (65.6% [60.8-70.4%]). CONCLUSION The current diagnostic yield of NGS in IRDs is between 52-74%. The certainty of the evidence was judged as low or very low. A key limitation of the current evidence is the significant heterogeneity between studies. Adoption of standardized reporting guidelines could improve confidence in future meta-analyses.
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17
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Sangermano R, Biswas P, Sullivan LS, Place EM, Borooah S, Straubhaar J, Pierce EA, Daiger SP, Bujakowska KM, Ayaggari R. Identification of a novel large multigene deletion and a frameshift indel in PDE6B as the underlying cause of early-onset recessive rod-cone degeneration. Cold Spring Harb Mol Case Stud 2022; 8:a006247. [PMID: 36376065 PMCID: PMC9808551 DOI: 10.1101/mcs.a006247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/02/2022] [Indexed: 11/15/2022] Open
Abstract
A family, with two affected identical twins with early-onset recessive inherited retinal degeneration, was analyzed to determine the underlying genetic cause of pathology. Exome sequencing revealed a rare and previously reported causative variant (c.1923_1969delinsTCTGGG; p.Asn643Glyfs*29) in the PDE6B gene in the affected twins and their unaffected father. Further investigation, using genome sequencing, identified a novel ∼7.5-kb deletion (Chr 4:670,405-677,862del) encompassing the ATP5ME gene, part of the 5' UTR of MYL5, and a 378-bp (Chr 4:670,405-670,782) region from the 3' UTR of PDE6B in the affected twins and their unaffected mother. Both variants segregated with disease in the family. Analysis of the relative expression of PDE6B, in peripheral blood cells, also revealed a significantly lower level of PDE6B transcript in affected siblings compared to a normal control. PDE6B is associated with recessive rod-cone degeneration and autosomal dominant congenital stationary night blindness. Ophthalmic evaluation of these patients showed night blindness, fundus abnormalities, and peripheral vision loss, which are consistent with PDE6B-associated recessive retinal degeneration. These findings suggest that the loss of PDE6B transcript resulting from the compound heterozygous pathogenic variants is the underlying cause of recessive rod-cone degeneration in the study family.
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Affiliation(s)
- Riccardo Sangermano
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Pooja Biswas
- Shiley Eye Institute, University of California San Diego, La Jolla, California 92093, USA
| | - Lori S Sullivan
- Human Genetics Center, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Emily M Place
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Shyamanga Borooah
- Shiley Eye Institute, University of California San Diego, La Jolla, California 92093, USA
| | - Juerg Straubhaar
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Stephen P Daiger
- Human Genetics Center, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Kinga M Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Radha Ayaggari
- Shiley Eye Institute, University of California San Diego, La Jolla, California 92093, USA
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18
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Hitti-Malin RJ, Dhaenens CM, Panneman DM, Corradi Z, Khan M, den Hollander AI, Farrar GJ, Gilissen C, Hoischen A, van de Vorst M, Bults F, Boonen EGM, Saunders P, Roosing S, Cremers FPM. Using single molecule Molecular Inversion Probes as a cost-effective, high-throughput sequencing approach to target all genes and loci associated with macular diseases. Hum Mutat 2022; 43:2234-2250. [PMID: 36259723 PMCID: PMC10092144 DOI: 10.1002/humu.24489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/06/2022] [Accepted: 10/17/2022] [Indexed: 01/25/2023]
Abstract
Macular degenerations (MDs) are a subgroup of retinal disorders characterized by central vision loss. Knowledge is still lacking on the extent of genetic and nongenetic factors influencing inherited MD (iMD) and age-related MD (AMD) expression. Single molecule Molecular Inversion Probes (smMIPs) have proven effective in sequencing the ABCA4 gene in patients with Stargardt disease to identify associated coding and noncoding variation, however many MD patients still remain genetically unexplained. We hypothesized that the missing heritability of MDs may be revealed by smMIPs-based sequencing of all MD-associated genes and risk factors. Using 17,394 smMIPs, we sequenced the coding regions of 105 iMD and AMD-associated genes and noncoding or regulatory loci, known pseudo-exons, and the mitochondrial genome in two test cohorts that were previously screened for variants in ABCA4. Following detailed sequencing analysis of 110 probands, a diagnostic yield of 38% was observed. This established an ''MD-smMIPs panel," enabling a genotype-first approach in a high-throughput and cost-effective manner, whilst achieving uniform and high coverage across targets. Further analysis will identify known and novel variants in MD-associated genes to offer an accurate clinical diagnosis to patients. Furthermore, this will reveal new genetic associations for MD and potential genetic overlaps between iMD and AMD.
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Affiliation(s)
- Rebekkah J Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Claire-Marie Dhaenens
- Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience & Cognition, Univ. Lille, Lille, France
| | - Daan M Panneman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mubeen Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - G Jane Farrar
- The School of Genetics & Microbiology, The University of Dublin Trinity College, Dublin, Ireland
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Department of Internal Medicine, Radboud University Medical Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maartje van de Vorst
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Femke Bults
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Erica G M Boonen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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19
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Haer-Wigman L, den Ouden A, van Genderen MM, Kroes HY, Verheij J, Smailhodzic D, Hoekstra AS, Vijzelaar R, Blom J, Derks R, Tjon-Pon-Fong M, Yntema HG, Nelen MR, Vissers LELM, Lugtenberg D, Neveling K. Diagnostic analysis of the highly complex OPN1LW/OPN1MW gene cluster using long-read sequencing and MLPA. NPJ Genom Med 2022; 7:65. [PMID: 36351915 PMCID: PMC9646815 DOI: 10.1038/s41525-022-00334-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 10/14/2022] [Indexed: 11/10/2022] Open
Abstract
Pathogenic variants in the OPN1LW/OPN1MW gene cluster are causal for a range of mild to severe visual impairments with color deficiencies. The widely utilized short-read next-generation sequencing (NGS) is inappropriate for the analysis of the OPN1LW/OPN1MW gene cluster and many patients with pathogenic variants stay underdiagnosed. A diagnostic genetic assay was developed for the OPN1LW/OPN1MW gene cluster, consisting of copy number analysis via multiplex ligation-dependent probe amplification and sequence analysis via long-read circular consensus sequencing. Performance was determined on 50 clinical samples referred for genetic confirmation of the clinical diagnosis (n = 43) or carrier status analysis (n = 7). A broad range of pathogenic haplotypes were detected, including deletions, hybrid genes, single variants and combinations of variants. The developed genetic assay for the OPN1LW/OPN1MW gene cluster is a diagnostic test that can detect both structural and nucleotide variants with a straightforward analysis, improving diagnostic care of patients with visual impairment.
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Affiliation(s)
- Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Amber den Ouden
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maria M van Genderen
- Bartiméus Diagnostic Center for complex visual disorders, Zeist, The Netherlands
- Department of Ophthalmology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Hester Y Kroes
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Joke Verheij
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Dzenita Smailhodzic
- Bartiméus Diagnostic Center for complex visual disorders, Zeist, The Netherlands
- The Rotterdam Eye Hospital, Rotterdam, 3011 BH, The Netherlands
| | | | | | - Jan Blom
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronny Derks
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Menno Tjon-Pon-Fong
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Helger G Yntema
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marcel R Nelen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisenka E L M Vissers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dorien Lugtenberg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kornelia Neveling
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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20
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Multi-omics approach dissects cis-regulatory mechanisms underlying North Carolina macular dystrophy, a retinal enhanceropathy. Am J Hum Genet 2022; 109:2029-2048. [PMID: 36243009 PMCID: PMC9674966 DOI: 10.1016/j.ajhg.2022.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/28/2022] [Indexed: 01/26/2023] Open
Abstract
North Carolina macular dystrophy (NCMD) is a rare autosomal-dominant disease affecting macular development. The disease is caused by non-coding single-nucleotide variants (SNVs) in two hotspot regions near PRDM13 and by duplications in two distinct chromosomal loci, overlapping DNase I hypersensitive sites near either PRDM13 or IRX1. To unravel the mechanisms by which these variants cause disease, we first established a genome-wide multi-omics retinal database, RegRet. Integration of UMI-4C profiles we generated on adult human retina then allowed fine-mapping of the interactions of the PRDM13 and IRX1 promoters and the identification of eighteen candidate cis-regulatory elements (cCREs), the activity of which was investigated by luciferase and Xenopus enhancer assays. Next, luciferase assays showed that the non-coding SNVs located in the two hotspot regions of PRDM13 affect cCRE activity, including two NCMD-associated non-coding SNVs that we identified herein. Interestingly, the cCRE containing one of these SNVs was shown to interact with the PRDM13 promoter, demonstrated in vivo activity in Xenopus, and is active at the developmental stage when progenitor cells of the central retina exit mitosis, suggesting that this region is a PRDM13 enhancer. Finally, mining of single-cell transcriptional data of embryonic and adult retina revealed the highest expression of PRDM13 and IRX1 when amacrine cells start to synapse with retinal ganglion cells, supporting the hypothesis that altered PRDM13 or IRX1 expression impairs interactions between these cells during retinogenesis. Overall, this study provides insight into the cis-regulatory mechanisms of NCMD and supports that this condition is a retinal enhanceropathy.
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21
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A Novel Autosomal Recessive Variant of the NRL Gene Causing Enhanced S-Cone Syndrome: A Morpho-Functional Analysis of Two Unrelated Pediatric Patients. Diagnostics (Basel) 2022; 12:diagnostics12092183. [PMID: 36140584 PMCID: PMC9497687 DOI: 10.3390/diagnostics12092183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Enhanced S-cone syndrome (ESCS) is a rare autosomal recessive retinal degeneration mainly associated with pathogenic variations in the NR2E3 gene. Only a few pathogenic variations in the NRL gene associated with ESCS have been reported to date. Here, we describe the clinical and genetic findings of two unrelated pediatric patients with a novel frameshift homozygous variant in the NRL gene. Fundus examinations showed signs of peripheral degeneration in both patients, more severe in Proband 2, with relative sparing of the macular area. Spectral domain optical coherence tomography (SD-OCT) revealed a significant macular involvement with cysts in Proband 1, and minimal foveal alteration with peripheral retina involvement in Proband 2. Visual acuity was abnormal in both patients, but more severely affected in Proband 1 than Proband 2. The electroretinogram recordings showed reduced scotopic, mixed and single flash cone responses, with a typical supernormal S-cone response, meeting the criteria for a clinical diagnosis of ESCS in both patients. The present report expands the clinical and genetic spectrum of NRL-associated ESCS, and confirms the age-independent variability of phenotypic presentation already described in the NR2E3-associated ESCS.
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22
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Ganapathi M, Thomas-Wilson A, Buchovecky C, Dharmadhikari A, Barua S, Lee W, Ruan MZC, Soucy M, Ragi S, Tanaka J, Clark LN, Naini AB, Liao J, Mansukhani M, Tsang S, Jobanputra V. Clinical exome sequencing for inherited retinal degenerations at a tertiary care center. Sci Rep 2022; 12:9358. [PMID: 35672425 PMCID: PMC9174483 DOI: 10.1038/s41598-022-13026-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/19/2022] [Indexed: 11/18/2022] Open
Abstract
Inherited retinal degenerations are clinically and genetically heterogeneous diseases characterized by progressive deterioration of vision. This study aimed at assessing the diagnostic yield of exome sequencing (ES) for an unselected cohort of individuals with hereditary retinal disorders. It is a retrospective study of 357 unrelated affected individuals, diagnosed with retinal disorders who underwent clinical ES. Variants from ES were filtered, prioritized, and classified using the ACMG recommendations. Clinical diagnosis of the individuals included rod-cone dystrophy (60%), macular dystrophy (20%), cone-rod dystrophy (9%), cone dystrophy (4%) and other phenotypes (7%). Majority of the cases (74%) were singletons and 6% were trios. A confirmed molecular diagnosis was obtained in 24% of cases. In 6% of cases, two pathogenic variants were identified with phase unknown, bringing the potential molecular diagnostic rate to ~ 30%. Including the variants of uncertain significance (VUS), potentially significant findings were reported in 57% of cases. Among cases with a confirmed molecular diagnosis, variants in EYS, ABCA4, USH2A, KIZ, CERKL, DHDDS, PROM1, NR2E3, CNGB1, ABCC6, PRPH2, RHO, PRPF31, PRPF8, SNRNP200, RP1, CHM, RPGR were identified in more than one affected individual. Our results support the utility of clinical ES in the diagnosis of genetically heterogeneous retinal disorders.
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Affiliation(s)
- Mythily Ganapathi
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Amanda Thomas-Wilson
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Christie Buchovecky
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Avinash Dharmadhikari
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Subit Barua
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Winston Lee
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Merry Z C Ruan
- College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA
| | - Megan Soucy
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Sara Ragi
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Joy Tanaka
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Lorraine N Clark
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Ali B Naini
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Jun Liao
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Mahesh Mansukhani
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Stephen Tsang
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- Jonas Children's Vision Care, Bernard & Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative-Departments of Ophthalmology, Biomedical Engineering, Pathology & Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Vaidehi Jobanputra
- Laboratory of Personalized Genomic Medicine, Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY, USA.
- Precision Genomics Laboratory, Columbia University Irving Medical Center, 701 West 168th St., HHSC 1412, New York, NY, 10032, USA.
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23
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El-Asrag ME, Corton M, McKibbin M, Avila-Fernandez A, Mohamed MD, Blanco-Kelly F, Toomes C, Inglehearn CF, Ayuso C, Ali M. Novel homozygous mutations in the transcription factor NRL cause non-syndromic retinitis pigmentosa. Mol Vis 2022; 28:48-56. [PMID: 35693422 PMCID: PMC9122474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/15/2022] [Indexed: 11/02/2022] Open
Abstract
Purpose To describe the clinical phenotype and genetic basis of non-syndromic retinitis pigmentosa (RP) in one family and two sporadic cases with biallelic mutations in the transcription factor neural retina leucine zipper (NRL). Methods Exome sequencing was performed in one affected family member. Microsatellite genotyping was used for haplotype analysis. PCR and Sanger sequencing were used to confirm mutations in and screen other family members where they were available. The SMART tool for domain prediction helped us build the protein schematic diagram. Results For family MM1 of Pakistani origin, whole-exome sequencing and microsatellite genotyping revealed homozygosity on chromosome 14 and identified a homozygous stop-loss mutation in NRL, NM_006177.5: c.713G>T, p.*238Lext57, which is predicted to add an extra 57 amino acids to the normal protein chain. The variant segregated with disease symptoms in the family. For case RP-3051 of Spanish ancestry, clinical exome sequencing focusing on the morbid genome highlighted a homozygous nonsense mutation in NRL, c.238C>T, p.Gln80*, as the most likely disease candidate. For case RP-1553 of Romanian ethnicity, targeted-exome sequencing of 73 RP/LCA genes identified a homozygous nonsense mutation in NRL, c.544C>T, p.Gln182*. The variants were either rare or absent in the gnomAD database. Conclusions NRL mutations predominantly cause dominant retinal disease, but there have been five published reports of mutations causing recessive disease. Here, we present three further examples of recessive RP due to NRL mutations. The phenotypes observed are consistent with those in the previous reports, and the observed mutation types and distribution further confirm distinct patterns for variants in NRL causing recessive and dominant diseases.
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Affiliation(s)
- Mohammed E. El-Asrag
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, UK,Department of Zoology, Faculty of Science, Benha University, Benha, Egypt
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Martin McKibbin
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, UK,The Eye Department, St. James’s University Hospital, Leeds, UK
| | - Almudena Avila-Fernandez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | | | - Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Carmel Toomes
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, UK
| | - Chris F. Inglehearn
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, UK
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital- Universidad Autónoma de Madrid (IIS-FJD, UAM), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Manir Ali
- Division of Molecular Medicine, Leeds Institute of Medical Research, St. James’s University Hospital, University of Leeds, Leeds, UK
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24
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Wang J, Wang Y, Jiang Y, Li X, Xiao X, Li S, Jia X, Sun W, Wang P, Zhang Q. Autosomal Dominant Retinitis Pigmentosa-Associated TOPORS Protein Truncating Variants Are Exclusively Located in the Region of Amino Acid Residues 807 to 867. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 35579903 PMCID: PMC9123486 DOI: 10.1167/iovs.63.5.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Heterozygous truncating variants of TOPORS have been reported to cause autosomal dominant retinitis pigmentosa (adRP). The purpose of this study was to investigate whether all heterozygous truncating variants, including copy number variants (CNVs), are pathogenic. Methods TOPORS truncating variants were collected and reviewed through an in-house dataset and existing databases. Individuals with truncating variants underwent ophthalmological evaluation. Results Six truncating variants were detected in seven families. Three N-terminus truncating variants were detected in three families without RP, and the other three were identified in four unrelated families with typical RP. Based on the in-house dataset and published literature, 17 truncating variants were identified in 47 families with RP. All RP-associated truncating alleles, except one, were distributed in the last exon of TOPORS and clustered in amino acid residues 807 to 867 (46/47, 97.9%). Conversely, in the gnomAD database, only one truncating allele (1/27, 3.7%) was in this region, and the others were outside (26/27, 96.3%), suggesting that the pathogenic truncating variants were significantly clustered in residues 807 to 867 (χ2 = 65.6, P = 1.1 × 10–17). Additionally, three CNVs involving the N-terminus of TOPORS were recorded in control populations but were absent in affected patients. Conclusions This study suggests that all pathogenic truncating variants of TOPORS were clustered in residues 807 to 867, whereas the truncating variants outside this region and the CNVs involving the N-terminus were not associated with RP. A dominant-negative effect, rather than haploinsufficiency, is speculated to be the underlying pathogenesis. These findings provide valuable information for interpreting variation in TOPORS and other genes in similar situations, especially for CNVs.
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Affiliation(s)
- Junwen Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yingwei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yi Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xueqing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
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Roberts PA. Inverse Problem Reveals Conditions for Characteristic Retinal Degeneration Patterns in Retinitis Pigmentosa Under the Trophic Factor Hypothesis. Front Aging Neurosci 2022; 14:765966. [PMID: 35585866 PMCID: PMC9108254 DOI: 10.3389/fnagi.2022.765966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 03/21/2022] [Indexed: 12/05/2022] Open
Abstract
Retinitis pigmentosa (RP) is the most common inherited retinal dystrophy with a prevalence of about 1 in 4,000, affecting approximately 1.5 million people worldwide. Patients with RP experience progressive visual field loss as the retina degenerates, destroying light-sensitive photoreceptor cells (rods and cones), with rods affected earlier and more severely than cones. Spatio-temporal patterns of retinal degeneration in human RP have been well characterised; however, the mechanism(s) giving rise to these patterns have not been conclusively determined. One such mechanism, which has received a wealth of experimental support, is described by the trophic factor hypothesis. This hypothesis suggests that rods produce a trophic factor necessary for cone survival; the loss of rods depletes this factor, leading to cone degeneration. In this article, we formulate a partial differential equation mathematical model of RP in one spatial dimension, spanning the region between the retinal centre (fovea) and the retinal edge (ora serrata). Using this model we derive and solve an inverse problem, revealing for the first time experimentally testable conditions under which the trophic factor mechanism will qualitatively recapitulate the spatio-temporal patterns of retinal regeneration observed in human RP.
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26
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Genetic characteristics of 234 Italian patients with macular and cone/cone-rod dystrophy. Sci Rep 2022; 12:3774. [PMID: 35260635 PMCID: PMC8904500 DOI: 10.1038/s41598-022-07618-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 02/16/2022] [Indexed: 01/09/2023] Open
Abstract
Two-hundred and thirty-four Italian patients with a clinical diagnosis of macular, cone and cone-rod dystrophies (MD, CD, and CRD) were examined using next-generation sequencing (NGS) and gene sequencing panels targeting a specific set of genes, Sanger sequencing and—when necessary—multiplex ligation-dependent probe amplification (MLPA) to diagnose the molecular cause of the aforementioned diseases. When possible, segregation analysis was performed in order to confirm unsolved cases. Each patient’s retinal phenotypic characteristics were determined using focal and full-field ERGs, perimetry, spectral domain optical coherence tomography and fundus autofluorescence. We identified 236 potentially causative variants in 136 patients representing the 58.1% of the total cohort, 43 of which were unpublished. After stratifying the patients according to their clinical suspicion, the diagnostic yield was 62.5% and 53.8% for patients with MD and for those with CD/CRD, respectively. The mode of inheritance of all cases confirmed by genetic analysis was 70% autosomal recessive, 26% dominant, and 4% X-linked. The main cause (59%) of both MD and CD/CRD cases was the presence of variants in the ABCA4 gene, followed by variants in PRPH2 (9%) and BEST1 (6%). A careful morpho-functional evaluation of the phenotype, together with genetic counselling, resulted in an acceptable diagnostic yield in a large cohort of Italian patients. Our study emphasizes the role of targeted NGS to diagnose MDs, CDs, and CRDs, as well as the clinical usefulness of segregation analysis for patients with unsolved diagnosis.
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Sallum JMF, Kaur VP, Shaikh J, Banhazi J, Spera C, Aouadj C, Viriato D, Fischer MD. Epidemiology of Mutations in the 65-kDa Retinal Pigment Epithelium (RPE65) Gene-Mediated Inherited Retinal Dystrophies: A Systematic Literature Review. Adv Ther 2022; 39:1179-1198. [PMID: 35098484 PMCID: PMC8918161 DOI: 10.1007/s12325-021-02036-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/22/2021] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Inherited retinal dystrophies (IRDs) represent a genetically diverse group of progressive, visually debilitating diseases. Adult and paediatric patients with vision loss due to IRD caused by biallelic mutations in the 65-kDa retinal pigment epithelium (RPE65) gene are often clinically diagnosed as retinitis pigmentosa (RP), and Leber congenital amaurosis (LCA). This study aimed to understand the epidemiological landscape of RPE65 gene-mediated IRD through a systematic review of the literature, as the current evidence base for its epidemiology is very limited. METHODS Medline, Embase, and other databases were searched for articles on the epidemiology of RPE65 gene-mediated IRDs from inception until June 2021. Studies were included if they were original research articles reporting the epidemiology of RP and LCA and/or proportion of RPE65 gene mutations in these clinically diagnosed or molecularly confirmed IRDs patients. RESULTS A total of 100 studies with relevant data were included in this systematic review. The range for prevalence of LCA and RP in the literature was 1.20-2.37 and 11.09-26.43 per 100,000, respectively. The proportion of RPE65 mutations in clinically diagnosed patients with LCA was found to be between ~ 2-16% within the US and major European countries (France, Germany, Italy, Spain, and the UK). This range was also comparable to our findings in the Asian region for RPE65-LCA (1.26-16.67%). Similarly, for these European countries, RPE65-RP was estimated between 0.23 and 1.94%, and RPE65-IRD range was 1.2-14%. Further, in the Americas region, mutations in RPE65 were reported to cause 1-3% of RP and 0.8-3.7% of IRD cases. Lastly, the RPE65-IRD range was 4.81-8% in the Middle East region. CONCLUSIONS There are significant variations in reporting of RPE65 proportions within countries as well as regions. Generating robust epidemiological evidence on RPE65 gene-mediated IRDs would be fundamental to support rare disease awareness, timely therapeutic intervention, and public health decision-making.
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Affiliation(s)
- Juliana M F Sallum
- Department of Ophthalmology, Universidade Federal de São Paulo, São Paulo, Brazil
- Instituto de Genética Ocular, São Paulo, Brazil
| | | | | | | | | | | | | | - M Dominik Fischer
- Centre for Ophthalmology, University Eye Hospital, University Hospital Tübingen, Tübingen, Germany
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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28
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Velde HM, Reurink J, Held S, Li CHZ, Yzer S, Oostrik J, Weeda J, Haer-Wigman L, Yntema HG, Roosing S, Pauleikhoff L, Lange C, Whelan L, Dockery A, Zhu J, Keegan DJ, Farrar GJ, Kremer H, Lanting CP, Damme M, Pennings RJE. Usher syndrome type IV: clinically and molecularly confirmed by novel ARSG variants. Hum Genet 2022; 141:1723-1738. [PMID: 35226187 PMCID: PMC9556359 DOI: 10.1007/s00439-022-02441-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/10/2022] [Indexed: 12/16/2022]
Abstract
AbstractUsher syndrome (USH) is an autosomal recessively inherited disease characterized by sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP) with or without vestibular dysfunction. It is highly heterogeneous both clinically and genetically. Recently, variants in the arylsulfatase G (ARSG) gene have been reported to underlie USH type IV. This distinct type of USH is characterized by late-onset RP with predominantly pericentral and macular changes, and late onset SNHL without vestibular dysfunction. In this study, we describe the USH type IV phenotype in three unrelated subjects. We identified three novel pathogenic variants, two novel likely pathogenic variants, and one previously described pathogenic variant in ARSG. Functional experiments indicated a loss of sulfatase activity of the mutant proteins. Our findings confirm that ARSG variants cause the newly defined USH type IV and support the proposed extension of the phenotypic USH classification.
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Affiliation(s)
- Hedwig M. Velde
- Hearing and Genes, Department of Otorhinolaryngology, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Janine Reurink
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
| | - Sebastian Held
- Department of Biochemistry, University of Kiel, Kiel, Germany
| | - Catherina H. Z. Li
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Ophthalmology, Radboudumc, Nijmegen, The Netherlands
| | - Suzanne Yzer
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Ophthalmology, Radboudumc, Nijmegen, The Netherlands
| | - Jaap Oostrik
- Hearing and Genes, Department of Otorhinolaryngology, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Jack Weeda
- Department of Ophthalmology, Radboudumc, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
| | - Helger G. Yntema
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
| | - Susanne Roosing
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
| | - Laurenz Pauleikhoff
- Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Clemens Lange
- Eye Center, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Laura Whelan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Adrian Dockery
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
- Next Generation Sequencing Laboratory, Pathology Department, The Mater Misericordiae University Hospital, Dublin, Ireland
| | - Julia Zhu
- Mater Clinical Ophthalmic Genetics Unit, The Mater Misericordiae University Hospital, Dublin, Ireland
| | - David J. Keegan
- Mater Clinical Ophthalmic Genetics Unit, The Mater Misericordiae University Hospital, Dublin, Ireland
| | - G. Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Hannie Kremer
- Hearing and Genes, Department of Otorhinolaryngology, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
| | - Cornelis P. Lanting
- Hearing and Genes, Department of Otorhinolaryngology, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
| | - Markus Damme
- Department of Biochemistry, University of Kiel, Kiel, Germany
| | - Ronald J. E. Pennings
- Hearing and Genes, Department of Otorhinolaryngology, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboudumc, Nijmegen, The Netherlands
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Veldman A, Kiewiet MBG, Heiner-Fokkema MR, Nelen MR, Sinke RJ, Sikkema-Raddatz B, Voorhoeve E, Westra D, Dollé MET, Schielen PCJI, van Spronsen FJ. Towards Next-Generation Sequencing (NGS)-Based Newborn Screening: A Technical Study to Prepare for the Challenges Ahead. Int J Neonatal Screen 2022; 8:ijns8010017. [PMID: 35323196 PMCID: PMC8949100 DOI: 10.3390/ijns8010017] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/28/2022] [Accepted: 02/08/2022] [Indexed: 01/27/2023] Open
Abstract
Newborn screening (NBS) aims to identify neonates with severe conditions for whom immediate treatment is required. Currently, a biochemistry-first approach is used to identify these disorders, which are predominantly inherited meta1bolic disorders (IMD). Next-generation sequencing (NGS) is expected to have some advantages over the current approach, for example the ability to detect IMDs that meet all screening criteria but lack an identifiable biochemical footprint. We have now designed a technical study to explore the use of NGS techniques as a first-tier approach in NBS. Here, we describe the aim and set-up of the NGS-first for the NBS (NGSf4NBS) project, which will proceed in three steps. In Step 1, we will identify IMDs eligible for NGS-first testing, based on treatability. In Step 2, we will investigate the feasibility, limitations and comparability of different technical NGS approaches and analysis workflows for NBS, eventually aiming to develop a rapid NGS-based workflow. Finally, in Step 3, we will prepare for the incorporation of this workflow into the existing Dutch NBS program and propose a protocol for referral of a child after a positive NGS test result. The results of this study will be the basis for an additional analytical route within NBS that will be further studied for its applicability within the NBS program, e.g., regarding the ethical, legal, financial and social implications.
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Affiliation(s)
- Abigail Veldman
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
- Correspondence: (A.V.); (M.B.G.K.)
| | - Mensiena B. G. Kiewiet
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.J.S.); (B.S.-R.)
- Correspondence: (A.V.); (M.B.G.K.)
| | - Margaretha Rebecca Heiner-Fokkema
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
| | - Marcel R. Nelen
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands; (M.R.N.); (D.W.)
| | - Richard J. Sinke
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.J.S.); (B.S.-R.)
| | - Birgit Sikkema-Raddatz
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.J.S.); (B.S.-R.)
| | - Els Voorhoeve
- Centre for Health Protection, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands; (E.V.); (M.E.T.D.)
| | - Dineke Westra
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands; (M.R.N.); (D.W.)
| | - Martijn E. T. Dollé
- Centre for Health Protection, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands; (E.V.); (M.E.T.D.)
| | - Peter C. J. I. Schielen
- Centre for Population Screening, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands;
| | - Francjan J. van Spronsen
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
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30
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Clinical and Genetic Re-Evaluation of Inherited Retinal Degeneration Pedigrees following Initial Negative Findings on Panel-Based Next Generation Sequencing. Int J Mol Sci 2022; 23:ijms23020995. [PMID: 35055178 PMCID: PMC8780304 DOI: 10.3390/ijms23020995] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/03/2022] [Accepted: 01/12/2022] [Indexed: 02/06/2023] Open
Abstract
Although rare, inherited retinal degenerations (IRDs) are the most common reason for blind registration in the working age population. They are highly genetically heterogeneous (>300 known genetic loci), and confirmation of a molecular diagnosis is a prerequisite for many therapeutic clinical trials and approved treatments. First-tier genetic testing of IRDs with panel-based next-generation sequencing (pNGS) has a diagnostic yield of ≈70-80%, leaving the remaining more challenging cases to be resolved by second-tier testing methods. This study describes the phenotypic reassessment of patients with a negative result from first-tier pNGS and the rationale, outcomes, and cost of second-tier genetic testing approaches. Removing non-IRD cases from consideration and utilizing case-appropriate second-tier genetic testing techniques, we genetically resolved 56% of previously unresolved pedigrees, bringing the overall resolve rate to 92% (388/423). At present, pNGS remains the most cost-effective first-tier approach for the molecular assessment of diverse IRD populations Second-tier genetic testing should be guided by clinical (i.e., reassessment, multimodal imaging, electrophysiology), and genetic (i.e., single alleles in autosomal recessive disease) indications to achieve a genetic diagnosis in the most cost-effective manner.
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Functional assays of non-canonical splice-site variants in inherited retinal dystrophies genes. Sci Rep 2022; 12:68. [PMID: 34996991 PMCID: PMC8742059 DOI: 10.1038/s41598-021-03925-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/10/2021] [Indexed: 11/17/2022] Open
Abstract
Inherited retinal dystrophies are a group of disorders characterized by the progressive degeneration of photoreceptors leading to loss of the visual function and eventually to legal blindness. Although next generation sequencing (NGS) has revolutionized the molecular diagnosis of these diseases, the pathogenicity of some mutations casts doubts. After the screening of 208 patients with a panel of 117 genes, we obtained 383 variants that were analysed in silico with bioinformatic prediction programs. Based on the results of these tools, we selected 15 variants for their functional assessment. Therefore, we carried out minigene assays to unveil whether they could affect the splicing of the corresponding gene. As a whole, seven variants were found to induce aberrant splicing in the following genes: BEST1, CACNA2D4, PRCD, RIMS1, FSCN2, MERTK and MAK. This study shows the efficacy of a workflow, based on the association of the Minimum Allele Frequency, family co-segregation, in silico predictions and in vitro assays to determine the effect of potential splice site variants identified by DNA-based NGS. These findings improve the molecular diagnosis of inherited retinal dystrophies and will allow some patients to benefit from the upcoming gene-based therapeutic strategies.
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32
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Daniute G, Vilkeviciute A, Gedvilaite G, Kriauciuniene L, Liutkeviciene R. RP1L1 rs3924612 gene polymorphism and RP1L1 protein associations among patients with early age-related macular degeneration. Ophthalmic Genet 2021; 43:164-171. [PMID: 34865606 DOI: 10.1080/13816810.2021.2010770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Age-related macular degeneration (AMD) is one of the most common causes of blindness in developed world countries. It mainly affects the elderly. The incidence of the disease is only slightly below that of cancer and cardiovascular diseases. This study aimed to determine the association of RP1L1 single nucleotide polymorphism and serum RP1L1 levels with the onset of the early AMD. AIM The aim of this study was to determine the association of RP1L1 single nucleotide polymorphism with the onset of the early age-related macular degeneration (AMD). METHODS The study examined 615 subjects: 309 with a diagnosis of the early AMD and 306 healthy controls. Samples of DNA from peripheral blood leukocytes were extracted by the DNA salting-out method. Genotyping was carried out by the real-time polymerase chain reaction. Serum levels of RP1L1 protein were evaluated using an ELISA kit. The results were assessed using the statistical analysis method of "IBM SPSS Statistics 23.0". RESULTS We have found that the RP1L1 rs3924612 C/G genotype increases the odds of the early AMD development in females (p <.05/2). Also, we found that RP1L1 rs3924612 C/G and G/G genotypes increase the odds of the early AMD in the age group of 56-68 years (p < .05/2). Serum RP1L1 levels were evaluated in study groups but no statistically significant associations were found. CONCLUSION Based on these results we concluded that RP1L1 rs3924612 polymorphism was associated with the early AMD development, but not with the RP1L1 level changes.
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Affiliation(s)
- Ginte Daniute
- Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Alvita Vilkeviciute
- Neuroscience Institute, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Greta Gedvilaite
- Neuroscience Institute, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Loresa Kriauciuniene
- Neuroscience Institute, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Rasa Liutkeviciene
- Neuroscience Institute, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
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Dingemans AJM, Hinne M, Jansen S, van Reeuwijk J, de Leeuw N, Pfundt R, van Bon BW, Vulto-van Silfhout AT, Kleefstra T, Koolen DA, van Gerven MAJ, Vissers LELM, de Vries BBA. Phenotype based prediction of exome sequencing outcome using machine learning for neurodevelopmental disorders. Genet Med 2021; 24:645-653. [PMID: 34906484 DOI: 10.1016/j.gim.2021.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/01/2021] [Accepted: 10/26/2021] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Although the introduction of exome sequencing (ES) has led to the diagnosis of a significant portion of patients with neurodevelopmental disorders (NDDs), the diagnostic yield in actual clinical practice has remained stable at approximately 30%. We hypothesized that improving the selection of patients to test on the basis of their phenotypic presentation will increase diagnostic yield and therefore reduce unnecessary genetic testing. METHODS We tested 4 machine learning methods and developed PredWES from these: a statistical model predicting the probability of a positive ES result solely on the basis of the phenotype of the patient. RESULTS We first trained the tool on 1663 patients with NDDs and subsequently showed that diagnostic ES on the top 10% of patients with the highest probability of a positive ES result would provide a diagnostic yield of 56%, leading to a notable 114% increase. Inspection of our model revealed that for patients with NDDs, comorbid abnormal (lower) muscle tone and microcephaly positively correlated with a conclusive ES diagnosis, whereas autism was negatively associated with a molecular diagnosis. CONCLUSION In conclusion, PredWES allows prioritizing patients with NDDs eligible for diagnostic ES on the basis of their phenotypic presentation to increase the diagnostic yield, making a more efficient use of health care resources.
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Affiliation(s)
- Alexander J M Dingemans
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands; Department of Artificial Intelligence, Faculty of Social Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Max Hinne
- Department of Artificial Intelligence, Faculty of Social Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Sandra Jansen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Jeroen van Reeuwijk
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Nicole de Leeuw
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Bregje W van Bon
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Anneke T Vulto-van Silfhout
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - David A Koolen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Marcel A J van Gerven
- Department of Artificial Intelligence, Faculty of Social Sciences, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Lisenka E L M Vissers
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands
| | - Bert B A de Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Radboud University, Nijmegen, The Netherlands.
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Schneider N, Sundaresan Y, Gopalakrishnan P, Beryozkin A, Hanany M, Levanon EY, Banin E, Ben-Aroya S, Sharon D. Inherited retinal diseases: Linking genes, disease-causing variants, and relevant therapeutic modalities. Prog Retin Eye Res 2021; 89:101029. [PMID: 34839010 DOI: 10.1016/j.preteyeres.2021.101029] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 12/11/2022]
Abstract
Inherited retinal diseases (IRDs) are a clinically complex and heterogenous group of visual impairment phenotypes caused by pathogenic variants in at least 277 nuclear and mitochondrial genes, affecting different retinal regions, and depleting the vision of affected individuals. Genes that cause IRDs when mutated are unique by possessing differing genotype-phenotype correlations, varying inheritance patterns, hypomorphic alleles, and modifier genes thus complicating genetic interpretation. Next-generation sequencing has greatly advanced the identification of novel IRD-related genes and pathogenic variants in the last decade. For this review, we performed an in-depth literature search which allowed for compilation of the Global Retinal Inherited Disease (GRID) dataset containing 4,798 discrete variants and 17,299 alleles published in 31 papers, showing a wide range of frequencies and complexities among the 194 genes reported in GRID, with 65% of pathogenic variants being unique to a single individual. A better understanding of IRD-related gene distribution, gene complexity, and variant types allow for improved genetic testing and therapies. Current genetic therapeutic methods are also quite diverse and rely on variant identification, and range from whole gene replacement to single nucleotide editing at the DNA or RNA levels. IRDs and their suitable therapies thus require a range of effective disease modelling in human cells, granting insight into disease mechanisms and testing of possible treatments. This review summarizes genetic and therapeutic modalities of IRDs, provides new analyses of IRD-related genes (GRID and complexity scores), and provides information to match genetic-based therapies such as gene-specific and variant-specific therapies to the appropriate individuals.
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Affiliation(s)
- Nina Schneider
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Yogapriya Sundaresan
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Prakadeeswari Gopalakrishnan
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Avigail Beryozkin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Mor Hanany
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel
| | - Shay Ben-Aroya
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Israel.
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35
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Fadaie Z, Whelan L, Ben-Yosef T, Dockery A, Corradi Z, Gilissen C, Haer-Wigman L, Corominas J, Astuti GDN, de Rooij L, van den Born LI, Klaver CCW, Hoyng CB, Wynne N, Duignan ES, Kenna PF, Cremers FPM, Farrar GJ, Roosing S. Whole genome sequencing and in vitro splice assays reveal genetic causes for inherited retinal diseases. NPJ Genom Med 2021; 6:97. [PMID: 34795310 PMCID: PMC8602293 DOI: 10.1038/s41525-021-00261-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 10/21/2021] [Indexed: 01/08/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a major cause of visual impairment. These clinically heterogeneous disorders are caused by pathogenic variants in more than 270 genes. As 30-40% of cases remain genetically unexplained following conventional genetic testing, we aimed to obtain a genetic diagnosis in an IRD cohort in which the genetic cause was not found using whole-exome sequencing or targeted capture sequencing. We performed whole-genome sequencing (WGS) to identify causative variants in 100 unresolved cases. After initial prioritization, we performed an in-depth interrogation of all noncoding and structural variants in genes when one candidate variant was detected. In addition, functional analysis of putative splice-altering variants was performed using in vitro splice assays. We identified the genetic cause of the disease in 24 patients. Causative coding variants were observed in genes such as ATXN7, CEP78, EYS, FAM161A, and HGSNAT. Gene disrupting structural variants were also detected in ATXN7, PRPF31, and RPGRIP1. In 14 monoallelic cases, we prioritized candidate noncanonical splice sites or deep-intronic variants that were predicted to disrupt the splicing process based on in silico analyses. Of these, seven cases were resolved as they carried pathogenic splice defects. WGS is a powerful tool to identify causative variants residing outside coding regions or heterozygous structural variants. This approach was most efficient in cases with a distinct clinical diagnosis. In addition, in vitro splice assays provide important evidence of the pathogenicity of rare variants.
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Affiliation(s)
- Zeinab Fadaie
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura Whelan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Adrian Dockery
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jordi Corominas
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Galuh D N Astuti
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Division of Human Genetics, Center for Biomedical Research (CEBIOR), Faculty of Medicine, Diponegoro University, Semarang, Indonesia
| | - Laura de Rooij
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Niamh Wynne
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Emma S Duignan
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Paul F Kenna
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - G Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.
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Lessons learned from unsolicited findings in clinical exome sequencing of 16,482 individuals. Eur J Hum Genet 2021; 30:170-177. [PMID: 34697415 PMCID: PMC8821629 DOI: 10.1038/s41431-021-00964-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 08/02/2021] [Accepted: 09/09/2021] [Indexed: 12/31/2022] Open
Abstract
Unsolicited findings (UFs) are uncovered unintentionally and predispose to a disease unrelated to the clinical question. The frequency and nature of UFs uncovered in clinical practice remain largely unexplored. We here evaluated UFs identified during a 5-year period in which 16,482 index patients received clinical whole-exome sequencing (WES). UFs were identified in 0.58% (95/16,482) of index patients, indicating that the overall frequency of UFs in clinical WES is low. Fewer UFs were identified using restricted disease-gene panels (0.03%) than when using whole-exome/Mendeliome analysis (1.03%). The UF was disclosed to 86 of 95 individuals, for reasons of medical actionability. Only 61% of these UFs reside in a gene that is listed on the “ACMG59”-list, representing a list of 59 genes for which the American College of Medical Genetics recommends UF disclosure. The remaining 39% were grouped into four categories: disorders similar to “ACMG59”-listed disorders (25%); disorders for which disease manifestation could be influenced (7%); UFs providing reproductive options (2%); and UFs with pharmacogenetic implications (5%). Hence, our experience shows that UFs predisposing to medically actionable disorders affect a broader range of genes than listed on the “ACMG59”, advocating that a pre-defined gene list is too restrictive, and that UFs may require ad hoc evaluation of medical actionability. While both the identification and disclosure of UFs depend on local policy, our lessons learned provide general essential insight into the nature and odds of UFs in clinical exome sequencing.
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Biswas P, Villanueva AL, Soto-Hermida A, Duncan JL, Matsui H, Borooah S, Kurmanov B, Richard G, Khan SY, Branham K, Huang B, Suk J, Bakall B, Goldberg JL, Gabriel L, Khan NW, Raghavendra PB, Zhou J, Devalaraja S, Huynh A, Alapati A, Zawaydeh Q, Weleber RG, Heckenlively JR, Hejtmancik JF, Riazuddin S, Sieving PA, Riazuddin SA, Frazer KA, Ayyagari R. Deciphering the genetic architecture and ethnographic distribution of IRD in three ethnic populations by whole genome sequence analysis. PLoS Genet 2021; 17:e1009848. [PMID: 34662339 PMCID: PMC8589175 DOI: 10.1371/journal.pgen.1009848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 11/12/2021] [Accepted: 09/29/2021] [Indexed: 12/12/2022] Open
Abstract
Patients with inherited retinal dystrophies (IRDs) were recruited from two understudied populations: Mexico and Pakistan as well as a third well-studied population of European Americans to define the genetic architecture of IRD by performing whole-genome sequencing (WGS). Whole-genome analysis was performed on 409 individuals from 108 unrelated pedigrees with IRDs. All patients underwent an ophthalmic evaluation to establish the retinal phenotype. Although the 108 pedigrees in this study had previously been examined for mutations in known IRD genes using a wide range of methodologies including targeted gene(s) or mutation(s) screening, linkage analysis and exome sequencing, the gene mutations responsible for IRD in these 108 pedigrees were not determined. WGS was performed on these pedigrees using Illumina X10 at a minimum of 30X depth. The sequence reads were mapped against hg19 followed by variant calling using GATK. The genome variants were annotated using SnpEff, PolyPhen2, and CADD score; the structural variants (SVs) were called using GenomeSTRiP and LUMPY. We identified potential causative sequence alterations in 61 pedigrees (57%), including 39 novel and 54 reported variants in IRD genes. For 57 of these pedigrees the observed genotype was consistent with the initial clinical diagnosis, the remaining 4 had the clinical diagnosis reclassified based on our findings. In seven pedigrees (12%) we observed atypical causal variants, i.e. unexpected genotype(s), including 4 pedigrees with causal variants in more than one IRD gene within all affected family members, one pedigree with intrafamilial genetic heterogeneity (different affected family members carrying causal variants in different IRD genes), one pedigree carrying a dominant causative variant present in pseudo-recessive form due to consanguinity and one pedigree with a de-novo variant in the affected family member. Combined atypical and large structural variants contributed to about 20% of cases. Among the novel mutations, 75% were detected in Mexican and 50% found in European American pedigrees and have not been reported in any other population while only 20% were detected in Pakistani pedigrees and were not previously reported. The remaining novel IRD causative variants were listed in gnomAD but were found to be very rare and population specific. Mutations in known IRD associated genes contributed to pathology in 63% Mexican, 60% Pakistani and 45% European American pedigrees analyzed. Overall, contribution of known IRD gene variants to disease pathology in these three populations was similar to that observed in other populations worldwide. This study revealed a spectrum of mutations contributing to IRD in three populations, identified a large proportion of novel potentially causative variants that are specific to the corresponding population or not reported in gnomAD and shed light on the genetic architecture of IRD in these diverse global populations. The study was performed to identify the underlying cause of inherited retinal degeneration (IRD) in 409 individuals from 108 families. Primarily, these families were recruited from three different geographic regions: Mexico, Pakistan and European Americans from the United States. Blood samples were collected from all individuals for genome analysis. This analysis detected causative variants in 61 out of the 108 pedigrees. A total of 93 gene variants were found in the 61 families. Among these, 54 were previously reported as causative variants and the remaining 39 have not been reported in IRD pedigrees. Interestingly, 54% of these novel variants were not listed in gnomAD. In addition to these findings, complex causative genotypes were observed in 20% of pedigrees. Overall, causative variants were detected in 63% Mexican, 60% Pakistani and 45% European American pedigrees. This study revealed the distribution of IRD causative variants in pedigrees with diverse ethnic and geographic backgrounds.
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Affiliation(s)
- Pooja Biswas
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
- School of Biotechnology, REVA University, Bengaluru, Karnataka, India
| | - Adda L. Villanueva
- Retina and Genomics Institute, Yucatán, México
- Laboratoire de Diagnostic Moleculaire, Hôpital Maisonneuve Rosemont, Montreal, Quebec, Canada
| | - Angel Soto-Hermida
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Jacque L. Duncan
- Ophthalmology, University of California San Francisco, San Francisco, California, United States of America
| | - Hiroko Matsui
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Shyamanga Borooah
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Berzhan Kurmanov
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | | | - Shahid Y. Khan
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Kari Branham
- Ophthalmology & Visual Science, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States of America
| | - Bonnie Huang
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - John Suk
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Benjamin Bakall
- Ophthalmology, University of Arizona College of Medicine Phoenix, Phoenix, Arizona, United States of America
| | - Jeffrey L. Goldberg
- Byers Eye Institute, Stanford, Palo Alto, California, United States of America
| | - Luis Gabriel
- Genetics and Ophthalmology, Genelabor, Goiânia, Brazil
| | - Naheed W. Khan
- Ophthalmology & Visual Science, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States of America
| | - Pongali B. Raghavendra
- School of Biotechnology, REVA University, Bengaluru, Karnataka, India
- School of Regenerative Medicine, Manipal University, Bengaluru, Karnataka, India
| | - Jason Zhou
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Sindhu Devalaraja
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Andrew Huynh
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Akhila Alapati
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Qais Zawaydeh
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
| | - Richard G. Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - John R. Heckenlively
- Ophthalmology & Visual Science, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan, United States of America
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan
| | - Paul A. Sieving
- National Eye Institute, Bethesda, Maryland, United States of America
- Ophthalmology & Vision Science, UC Davis Medical Center, California, United States of America
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (RA); (KAF); (SAR)
| | - Kelly A. Frazer
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, California, United States of America
- Department of Pediatrics, Rady Children’s Hospital, Division of Genome Information Sciences, San Diego, California, United States of America
- * E-mail: (RA); (KAF); (SAR)
| | - Radha Ayyagari
- Shiley Eye Institute, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (RA); (KAF); (SAR)
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Long-read technologies identify a hidden inverted duplication in a family with choroideremia. HGG ADVANCES 2021; 2:100046. [PMID: 35047838 PMCID: PMC8756506 DOI: 10.1016/j.xhgg.2021.100046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/01/2021] [Indexed: 12/03/2022] Open
Abstract
The lack of molecular diagnoses in rare genetic diseases can be explained by limitations of current standard genomic technologies. Upcoming long-read techniques have complementary strengths to overcome these limitations, with a particular strength in identifying structural variants. By using optical genome mapping and long-read sequencing, we aimed to identify the pathogenic variant in a large family with X-linked choroideremia. In this family, aberrant splicing of exon 12 of the choroideremia gene CHM was detected in 2003, but the underlying genomic defect remained elusive. Optical genome mapping and long-read sequencing approaches now revealed an intragenic 1,752 bp inverted duplication including exon 12 and surrounding regions, located downstream of the wild-type copy of exon 12. Both breakpoint junctions were confirmed with Sanger sequencing and segregate with the X-linked inheritance in the family. The breakpoint junctions displayed sequence microhomology suggestive for an erroneous replication mechanism as the origin of the structural variant. The inverted duplication is predicted to result in a hairpin formation of the pre-mRNA with the wild-type exon 12, leading to exon skipping in the mature mRNA. The identified inverted duplication is deemed the hidden pathogenic cause of disease in this family. Our study shows that optical genome mapping and long-read sequencing have significant potential for the identification of (hidden) structural variants in rare genetic diseases.
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Mutated CCDC51 Coding for a Mitochondrial Protein, MITOK Is a Candidate Gene Defect for Autosomal Recessive Rod-Cone Dystrophy. Int J Mol Sci 2021; 22:ijms22157875. [PMID: 34360642 PMCID: PMC8346125 DOI: 10.3390/ijms22157875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/05/2021] [Accepted: 07/15/2021] [Indexed: 11/17/2022] Open
Abstract
The purpose of this work was to identify the gene defect underlying a relatively mild rod-cone dystrophy (RCD), lacking disease-causing variants in known genes implicated in inherited retinal disorders (IRD), and provide transcriptomic and immunolocalization data to highlight the best candidate. The DNA of the female patient originating from a consanguineous family revealed no large duplication or deletion, but several large homozygous regions. In one of these, a homozygous frameshift variant, c.244_246delins17 p.(Trp82Valfs*4); predicted to lead to a nonfunctional protein, was identified in CCDC51. CCDC51 encodes the mitochondrial coiled-coil domain containing 51 protein, also called MITOK. MITOK ablation causes mitochondrial dysfunction. Here we show for the first time that CCDC51/MITOK localizes in the retina and more specifically in the inner segments of the photoreceptors, well known to contain mitochondria. Mitochondrial proteins have previously been implicated in IRD, although usually in association with syndromic disease, unlike our present case. Together, our findings add another ultra-rare mutation implicated in non-syndromic IRD, whose pathogenic mechanism in the retina needs to be further elucidated.
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40
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Burdon KP. The utility of genomic testing in the ophthalmology clinic: A review. Clin Exp Ophthalmol 2021; 49:615-625. [PMID: 34231298 DOI: 10.1111/ceo.13970] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 12/25/2022]
Abstract
Genomic testing assesses many genes in one test. It is often used in the diagnosis of heterogeneous single gene disorders where pathogenic variation in one of many genes are known to cause similar phenotypes, or where a clinical diagnosis is difficult to reach. In the ophthalmic setting, genomic testing can be used to diagnose several groups of diseases, including inherited retinal dystrophies, paediatric cataract, glaucoma and anterior segment dysgenesis and other syndromic developmental disorders with eye involvement. The testing can encompass several modalities ranging from whole genome sequencing to exome sequencing or targeted gene panels. The advantages to the patient of receiving a molecular diagnosis include an end to the diagnostic odyssey, determination of prognosis and clarification of treatment, access to accurate genetic counselling, and confirming eligibility for clinical trials or genetic specific therapies. Genomic testing is a powerful addition to the diagnosis and management of inherited eye disease.
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Affiliation(s)
- Kathryn P Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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Aoun M, Passerini I, Chiurazzi P, Karali M, De Rienzo I, Sartor G, Murro V, Filimonova N, Seri M, Banfi S. Inherited Retinal Diseases Due to RPE65 Variants: From Genetic Diagnostic Management to Therapy. Int J Mol Sci 2021; 22:7207. [PMID: 34281261 PMCID: PMC8268668 DOI: 10.3390/ijms22137207] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/18/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a heterogeneous group of conditions that include retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) and early-onset severe retinal dystrophy (EO[S]RD), which differ in severity and age of onset. IRDs are caused by mutations in >250 genes. Variants in the RPE65 gene account for 0.6-6% of RP and 3-16% of LCA/EORD cases. Voretigene neparvovec is a gene therapy approved for the treatment of patients with an autosomal recessive retinal dystrophy due to confirmed biallelic RPE65 variants (RPE65-IRDs). Therefore, the accurate molecular diagnosis of RPE65-IRDs is crucial to identify 'actionable' genotypes-i.e., genotypes that may benefit from the treatment-and is an integral part of patient management. To date, hundreds of RPE65 variants have been identified, some of which are classified as pathogenic or likely pathogenic, while the significance of others is yet to be established. In this review, we provide an overview of the genetic diagnostic workup needed to select patients that could be eligible for voretigene neparvovec treatment. Careful clinical characterization of patients by multidisciplinary teams of experts, combined with the availability of next-generation sequencing approaches, can accelerate patients' access to available therapeutic options.
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Affiliation(s)
- Manar Aoun
- Novartis Farma, Largo Boccioni 1, 21040 Origgio, Italy;
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, 50134 Florence, Italy;
| | - Pietro Chiurazzi
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore, 00168 Rome, Italy;
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, UOC Genetica Medica, 00168 Roma, Italy
| | - Marianthi Karali
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, 80131 Naples, Italy;
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy
| | - Irene De Rienzo
- Department of Ophthalmology, AOU-Careggi, 50234 Florence, Italy;
| | - Giovanna Sartor
- Medical Genetics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy;
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic Careggi Teaching Hospital, 50234 Florence, Italy;
| | | | - Marco Seri
- Medical Genetics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy;
- Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy
- Medical Genetics, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
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Truncating SRCAP variants outside the Floating-Harbor syndrome locus cause a distinct neurodevelopmental disorder with a specific DNA methylation signature. Am J Hum Genet 2021; 108:1053-1068. [PMID: 33909990 PMCID: PMC8206150 DOI: 10.1016/j.ajhg.2021.04.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/31/2021] [Indexed: 02/08/2023] Open
Abstract
Truncating variants in exons 33 and 34 of the SNF2-related CREBBP activator protein (SRCAP) gene cause the neurodevelopmental disorder (NDD) Floating-Harbor syndrome (FLHS), characterized by short stature, speech delay, and facial dysmorphism. Here, we present a cohort of 33 individuals with clinical features distinct from FLHS and truncating (mostly de novo) SRCAP variants either proximal (n = 28) or distal (n = 5) to the FLHS locus. Detailed clinical characterization of the proximal SRCAP individuals identified shared characteristics: developmental delay with or without intellectual disability, behavioral and psychiatric problems, non-specific facial features, musculoskeletal issues, and hypotonia. Because FLHS is known to be associated with a unique set of DNA methylation (DNAm) changes in blood, a DNAm signature, we investigated whether there was a distinct signature associated with our affected individuals. A machine-learning model, based on the FLHS DNAm signature, negatively classified all our tested subjects. Comparing proximal variants with typically developing controls, we identified a DNAm signature distinct from the FLHS signature. Based on the DNAm and clinical data, we refer to the condition as “non-FLHS SRCAP-related NDD.” All five distal variants classified negatively using the FLHS DNAm model while two classified positively using the proximal model. This suggests divergent pathogenicity of these variants, though clinically the distal group presented with NDD, similar to the proximal SRCAP group. In summary, for SRCAP, there is a clear relationship between variant location, DNAm profile, and clinical phenotype. These results highlight the power of combined epigenetic, molecular, and clinical studies to identify and characterize genotype-epigenotype-phenotype correlations.
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Nassisi M, Smirnov VM, Solis Hernandez C, Mohand‐Saïd S, Condroyer C, Antonio A, Kühlewein L, Kempf M, Kohl S, Wissinger B, Nasser F, Ragi SD, Wang N, Sparrow JR, Greenstein VC, Michalakis S, Mahroo OA, Ba‐Abbad R, Michaelides M, Webster AR, Degli Esposti S, Saffren B, Capasso J, Levin A, Hauswirth WW, Dhaenens C, Defoort‐Dhellemmes S, Tsang SH, Zrenner E, Sahel J, Petersen‐Jones SM, Zeitz C, Audo I. CNGB1-related rod-cone dystrophy: A mutation review and update. Hum Mutat 2021; 42:641-666. [PMID: 33847019 PMCID: PMC8218941 DOI: 10.1002/humu.24205] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/26/2021] [Accepted: 04/08/2021] [Indexed: 12/29/2022]
Abstract
Cyclic nucleotide-gated channel β1 (CNGB1) encodes the 240-kDa β subunit of the rod photoreceptor cyclic nucleotide-gated ion channel. Disease-causing sequence variants in CNGB1 lead to autosomal recessive rod-cone dystrophy/retinitis pigmentosa (RP). We herein present a comprehensive review and analysis of all previously reported CNGB1 sequence variants, and add 22 novel variants, thereby enlarging the spectrum to 84 variants in total, including 24 missense variants (two of which may also affect splicing), 21 nonsense, 19 splicing defects (7 at noncanonical positions), 10 small deletions, 1 small insertion, 1 small insertion-deletion, 7 small duplications, and 1 gross deletion. According to the American College of Medical Genetics and Genomics classification criteria, 59 variants were considered pathogenic or likely pathogenic and 25 were variants of uncertain significance. In addition, we provide further phenotypic data from 34 CNGB1-related RP cases, which, overall, are in line with previous findings suggesting that this form of RP has long-term retention of useful central vision despite the early onset of night blindness, which is valuable for patient counseling, but also has implications for it being considered a priority target for gene therapy trials.
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Affiliation(s)
- Marco Nassisi
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Centre Hospitalier National d'Ophtalmologie des Quinze‐Vingts, INSERM‐DGOS CIC1423ParisFrance
- Department of Clinical Sciences and Community HealthUniversity of MilanMilanItaly
- Ophthalmological Unit, Fondazione IRCCS Ca' GrandaOspedale Maggiore PoliclinicoMilanItaly
| | - Vasily M. Smirnov
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Exploration de la vision et Neuro‐Ophthalmologie, CHU de LilleLilleFrance
- Faculté de MédecineUniversité de LilleLilleFrance
| | - Cyntia Solis Hernandez
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Saddek Mohand‐Saïd
- Centre Hospitalier National d'Ophtalmologie des Quinze‐Vingts, INSERM‐DGOS CIC1423ParisFrance
| | - Christel Condroyer
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Aline Antonio
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Laura Kühlewein
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
- Institute for Ophthalmic Research, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Melanie Kempf
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Fadi Nasser
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Sara D. Ragi
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
| | - Nan‐Kai Wang
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
- College of MedicineChang Gung UniversityTaoyuanTaiwan
- Department of Ophthalmology, Chang Gung Memorial HospitalLinkou Medical CenterTaoyuanTaiwan
| | - Janet R. Sparrow
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
| | | | | | - Omar A. Mahroo
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Rola Ba‐Abbad
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Michel Michaelides
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Andrew R. Webster
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Simona Degli Esposti
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Brooke Saffren
- Philadelphia College of Osteopathic MedicinePhiladelphiaPennsylvaniaUSA
| | | | - Alex Levin
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, Pediatric Genetics, Golisano Children's HospitalUniversity of RochesterRochesterNew YorkUSA
| | | | - Claire‐Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172‐LilNCog‐Lille Neuroscience & CognitionLilleFrance
| | | | - Stephen H. Tsang
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma LaboratoryNew YorkNew YorkUSA
- Department of Pathology and Cell BiologyColumbia UniversityNew YorkNew YorkUSA
- Stem Cell Initiative (CSCI), Institute of Human Nutrition, Vagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
| | - Eberhart Zrenner
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Jose‐Alain Sahel
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Department of OphthalmologyThe University of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
- Fondation Ophtalmologique Adolphe de RothschildParisFrance
| | - Simon M. Petersen‐Jones
- Department of Small Animal Clinical SciencesMichigan State UniversityEast LansingMichiganUSA
| | - Christina Zeitz
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Isabelle Audo
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Centre Hospitalier National d'Ophtalmologie des Quinze‐Vingts, INSERM‐DGOS CIC1423ParisFrance
- University College London Institute of OphthalmologyLondonUK
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Next-Generation Sequencing Applications for Inherited Retinal Diseases. Int J Mol Sci 2021; 22:ijms22115684. [PMID: 34073611 PMCID: PMC8198572 DOI: 10.3390/ijms22115684] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal diseases (IRDs) represent a collection of phenotypically and genetically diverse conditions. IRDs phenotype(s) can be isolated to the eye or can involve multiple tissues. These conditions are associated with diverse forms of inheritance, and variants within the same gene often can be associated with multiple distinct phenotypes. Such aspects of the IRDs highlight the difficulty met when establishing a genetic diagnosis in patients. Here we provide an overview of cutting-edge next-generation sequencing techniques and strategies currently in use to maximise the effectivity of IRD gene screening. These techniques have helped researchers globally to find elusive causes of IRDs, including copy number variants, structural variants, new IRD genes and deep intronic variants, among others. Resolving a genetic diagnosis with thorough testing enables a more accurate diagnosis and more informed prognosis and should also provide information on inheritance patterns which may be of particular interest to patients of a child-bearing age. Given that IRDs are heritable conditions, genetic counselling may be offered to help inform family planning, carrier testing and prenatal screening. Additionally, a verified genetic diagnosis may enable access to appropriate clinical trials or approved medications that may be available for the condition.
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Veldman BCF, Kuper WFE, Lilien M, Schuurs-Hoeijmakers JHM, Marcelis C, Phan M, Hettinga Y, Talsma HE, van Hasselt PM, Haijes HA. Beyond nephronophthisis: Retinal dystrophy in the absence of kidney dysfunction in childhood expands the clinical spectrum of CEP83 deficiency. Am J Med Genet A 2021; 185:2204-2210. [PMID: 33938610 PMCID: PMC8252653 DOI: 10.1002/ajmg.a.62225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/12/2022]
Abstract
The CEP83 protein is an essential part in the first steps of ciliogenesis, causing a ciliopathy if deficient. As a core component of the distal appendages of the centriole, CEP83 is located in almost all cell types and is involved in the primary cilium assembly. Previously reported CEP83 deficient patients all presented with nephronophthisis and kidney dysfunction. Despite retinal degeneration being a common feature in ciliopathies, only one patient also had retinitis. Here, we present two unrelated patients, who both presented with retinitis pigmentosa, without nephronophthisis or any form of kidney dysfunction. Both patients harbor bi‐allelic variants in CEP83. This report expands the current clinical spectrum of CEP83 deficiency. For timely diagnosis of CEP83 deficiency, we advocate that CEP83 should be included in gene panels for inherited retinal diseases.
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Affiliation(s)
- Bram C F Veldman
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Willemijn F E Kuper
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marc Lilien
- Department of Pediatric Nephrology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Carlo Marcelis
- Department of Clinical Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Milan Phan
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ymkje Hettinga
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - Herman E Talsma
- Bartiméus Diagnostic Center for Complex Visual Disorders, Zeist, The Netherlands
| | - Peter M van Hasselt
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Hanneke A Haijes
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
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Unique Variant Spectrum in a Jordanian Cohort with Inherited Retinal Dystrophies. Genes (Basel) 2021; 12:genes12040593. [PMID: 33921607 PMCID: PMC8074154 DOI: 10.3390/genes12040593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 04/07/2021] [Accepted: 04/14/2021] [Indexed: 12/12/2022] Open
Abstract
Whole Exome Sequencing (WES) is a powerful approach for detecting sequence variations in the human genome. The aim of this study was to investigate the genetic defects in Jordanian patients with inherited retinal dystrophies (IRDs) using WES. WES was performed on proband patients' DNA samples from 55 Jordanian families. Sanger sequencing was used for validation and segregation analysis of the detected, potential disease-causing variants (DCVs). Thirty-five putatively causative variants (6 novel and 29 known) in 21 IRD-associated genes were identified in 71% of probands (39 of the 55 families). Three families showed phenotypes different from the typically reported clinical findings associated with the causative genes. To our knowledge, this is the largest genetic analysis of IRDs in the Jordanian population to date. Our study also confirms that WES is a powerful tool for the molecular diagnosis of IRDs in large patient cohorts.
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Westin IM, Jonsson F, Österman L, Holmberg M, Burstedt M, Golovleva I. EYS mutations and implementation of minigene assay for variant classification in EYS-associated retinitis pigmentosa in northern Sweden. Sci Rep 2021; 11:7696. [PMID: 33833316 PMCID: PMC8032658 DOI: 10.1038/s41598-021-87224-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/25/2021] [Indexed: 11/24/2022] Open
Abstract
Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous group of inherited retinal degenerations. The ortholog of Drosophila eyes shut/spacemaker, EYS on chromosome 6q12 is a major genetic cause of recessive RP worldwide, with prevalence of 5 to 30%. In this study, by using targeted NGS, MLPA and Sanger sequencing we uncovered the EYS gene as one of the most common genetic cause of autosomal recessive RP in northern Sweden accounting for at least 16%. The most frequent pathogenic variant was c.8648_8655del that in some patients was identified in cis with c.1155T>A, indicating Finnish ancestry. We also showed that two novel EYS variants, c.2992_2992+6delinsTG and c.3877+1G>A caused exon skipping in human embryonic kidney cells, HEK293T and in retinal pigment epithelium cells, ARPE-19 demonstrating that in vitro minigene assay is a straightforward tool for the analysis of intronic variants. We conclude, that whenever it is possible, functional testing is of great value for classification of intronic EYS variants and the following molecular testing of family members, their genetic counselling, and inclusion of RP patients to future treatment studies.
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Affiliation(s)
- Ida Maria Westin
- Medical Biosciences/Medical and Clinical Genetics, University of Umeå, 901 87, Umeå, Sweden
| | - Frida Jonsson
- Medical Biosciences/Medical and Clinical Genetics, University of Umeå, 901 87, Umeå, Sweden
| | - Lennart Österman
- Medical Biosciences/Medical and Clinical Genetics, University of Umeå, 901 87, Umeå, Sweden
| | - Monica Holmberg
- Medical Biosciences/Medical and Clinical Genetics, University of Umeå, 901 87, Umeå, Sweden
| | - Marie Burstedt
- Clinical Science/Ophthalmology, University of Umeå, 901 85, Umeå, Sweden
| | - Irina Golovleva
- Medical Biosciences/Medical and Clinical Genetics, University of Umeå, 901 87, Umeå, Sweden.
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Ni SH, Zhang JM, Zhao J. A novel missense mutation of CRYBA1 in a northern Chinese family with inherited coronary cataract with blue punctate opacities. Eur J Ophthalmol 2021; 32:193-199. [PMID: 33827296 DOI: 10.1177/11206721211008355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To demonstrate the underlying genetic defect that contribute to inherited cataract in a northern Chinese pedigree. METHODS The study recruited a family pedigree with a diagnosis of bilateral coronary cataract with blue punctate opacities. Fourteen family members and 100 healthy volunteers were enrolled. DNA sample of the proband in this family were analyzed by high-throughput sequencing, which was then demonstrated by Sanger sequencing in the remained people in the family and 100 controls. The functional effect of mutant genes was investigated via bioinformatics analysis, including Polymorphism Phenotyping version2 (PolyPhen-2), Protein Variation Effect Analyzer (PROVEAN v1.1.3) Scale-Invariant Feature Transform (SIFT), and Mutation Taster. RESULTS In this three-generation family, a novel heterozygous mutation was found in the kinase domain of CRYBA1 gene (c.340C > T, p.R114C), which was only detected in patients in the family with inherited cataract and were not detected in the remained people in the family nor in normal people. The pathogenic effect of the mutation was verified via bioinformatics analysis. CONCLUSION Our study presented the molecular experiments to confirm that a novel missense mutation of c.340 C > T located in exon 4 of CRYBA1 gene results in a bilateral coronary cataract with blue punctate opacities, which enriches the mutation spectrum of CRYBA1 gene in inherited cataract and deepens the understanding of the pathogenesis of inherited cataract.
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Affiliation(s)
- Shu-Hua Ni
- School of Clinical Medicine, Weifang Medical University, Weifang, China
| | - Juan-Mei Zhang
- Department of Ophthalmology, Linyi People's Hospital, Linyi, China
| | - Jun Zhao
- Department of Ophthalmology, Linyi People's Hospital, Linyi, China
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Bai Z, Xie Y, Liu L, Shao J, Liu Y, Kong X. Genetic investigation of 211 Chinese families expands the mutational and phenotypical spectra of hereditary retinopathy genes through targeted sequencing technology. BMC Med Genomics 2021; 14:92. [PMID: 33781268 PMCID: PMC8008643 DOI: 10.1186/s12920-021-00935-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 03/08/2021] [Indexed: 11/15/2022] Open
Abstract
Background Hereditary retinopathy is a significant cause of blindness worldwide. Despite the discovery of many mutations in various retinopathies, a large number of patients remain genetically undiagnosed. Targeted next-generation sequencing of the human genome is a suitable approach for the molecular diagnosis of retinopathy. Methods We describe a cohort of 211 families from central China with various forms of retinopathy; 95 patients were investigated using multigene panel sequencing, and the other 116 with suspected Leber hereditary optic neuropathy (LHON) were tested by Sanger sequencing. The detected variation of targeted sequencing was verified by PCR-based Sanger sequencing. We performed a comprehensive analysis of the cases using sequencing data and ophthalmologic examination information. Results Potential causal mutations were identified in the majority of families with retinopathy (57.9% of 95 families) and suspected LHON (21.6% of 116 families). There were 68 variants of a certain significance distributed in 31 known disease-causing genes in the 95 families; 37 of the variants are novel and have not been reported to be related to hereditary retinopathy. The NGS panel solution provided a 45.3% potential diagnostic rate for retinopathy families, with candidate gene mutations of undefined pathogenicity revealed in another 12.6%of the families. Conclusion Our study uncovered novel mutations and phenotypic aspects of retinopathy and demonstrated the genetic and clinical heterogeneity of related conditions. The findings show the detection rate of pathogenic variants in patients with hereditary retinopathy in central China as well as the diversity and gene distribution of these variants. The significance of molecular genetic testing for patients with hereditary retinopathy is also highlighted. Supplementary Information The online version contains supplementary material available at 10.1186/s12920-021-00935-w.
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Affiliation(s)
- Zhouxian Bai
- The Genetics and Prenatal Diagnosis Center, The Department of Obstetrics and Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China
| | - Yanchuan Xie
- The Department of Central Laboratory, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, 471003, Henan, China
| | - Lina Liu
- The Genetics and Prenatal Diagnosis Center, The Department of Obstetrics and Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China
| | - Jingzhi Shao
- The Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China
| | - Yuying Liu
- The Physical Examination Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China
| | - Xiangdong Kong
- The Genetics and Prenatal Diagnosis Center, The Department of Obstetrics and Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China.
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The need for widely available genomic testing in rare eye diseases: an ERN-EYE position statement. Orphanet J Rare Dis 2021; 16:142. [PMID: 33743793 PMCID: PMC7980559 DOI: 10.1186/s13023-021-01756-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/18/2021] [Indexed: 12/26/2022] Open
Abstract
Background Rare Eye Diseases (RED) are the leading cause of visual impairment and blindness for children and young adults in Europe. This heterogeneous group of conditions includes over 900 disorders ranging from relatively prevalent disorders such as retinitis pigmentosa to very rare entities such as developmental eye anomalies. A significant number of patients with RED have an underlying genetic etiology. One of the aims of the European Reference Network for Rare Eye Diseases (ERN–EYE) is to facilitate improvement in diagnosis of RED in European member states. Main body Technological advances have allowed genetic and genomic testing for RED. The outcome of genetic testing allows better understanding of the condition and allows reproductive and therapeutic options. The increase of the number of clinical trials for RED has provided urgency for genetic testing in RED. A survey of countries participating in ERN-EYE demonstrated that the majority are able to access some forms of genomic testing. However, there is significant variability, particularly regarding testing as part of clinical service. Some countries have a well-delineated rare disease pathway and have a national plan for rare diseases combined or not with a national plan for genomics in medicine. In other countries, there is a well-established organization of genetic centres that offer reimbursed genomic testing of RED and other rare diseases. Clinicians often rely upon research-funded laboratories or private companies. Notably, some member states rely on cross-border testing by way of an academic research project. Consequently, many clinicians are either unable to access testing or are confronted with long turnaround times. Overall, while the cost of sequencing has dropped, the cumulative cost of a genomic testing service for populations remains considerable. Importantly, the majority of countries reported healthcare budgets that limit testing. Short conclusion Despite technological advances, critical gaps in genomic testing remain in Europe, especially in smaller countries where no formal genomic testing pathways exist. Even within larger countries, the existing arrangements are insufficient to meet the demand and to ensure access. ERN-EYE promotes access to genetic testing in RED and emphasizes the clinical need and relevance of genetic testing in RED.
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